CA2211301C - Network security device - Google Patents
Network security device Download PDFInfo
- Publication number
- CA2211301C CA2211301C CA002211301A CA2211301A CA2211301C CA 2211301 C CA2211301 C CA 2211301C CA 002211301 A CA002211301 A CA 002211301A CA 2211301 A CA2211301 A CA 2211301A CA 2211301 C CA2211301 C CA 2211301C
- Authority
- CA
- Canada
- Prior art keywords
- network
- node
- security device
- address
- packet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/02—Network architectures or network communication protocols for network security for separating internal from external traffic, e.g. firewalls
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/04—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks
- H04L63/0428—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/04—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks
- H04L63/0428—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload
- H04L63/0442—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/06—Network architectures or network communication protocols for network security for supporting key management in a packet data network
- H04L63/068—Network architectures or network communication protocols for network security for supporting key management in a packet data network using time-dependent keys, e.g. periodically changing keys
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/16—Implementing security features at a particular protocol layer
- H04L63/164—Implementing security features at a particular protocol layer at the network layer
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0838—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these
- H04L9/0841—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these involving Diffie-Hellman or related key agreement protocols
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/40—Network security protocols
Abstract
A network security device (10) is connected between a protected client (12) and a network (100). The network security device (10) negotiates a session key with any other protected client. Then, all communications between the two clients are encrypted. The inventive device is self-configuring and locks itself to the IP address of its client (12). Thus, the client (12) cannot change its IP address once set and therefore cannot emulate the IP address of another client. When a packet is transmitted from the protected host, the security device (10) translates the MAC address of the client to its own MAC address before transmitting the packet into the network. Packets addressed to the host, contain the MAC address of the security device. The security device (10) translates its MAC address to the client's (12) MAC address before transmitting the packet to the client (12).
Description
... . . . CA 02211301 2005-05-13 WO 97/13340 PCTlUS96/14285 NETVrTORK SECURITY DEVICE
Field of the Invention The present invention is directed to a network security device that is connected between a protected computer (the client) and a network and a method for utilizing the network security device. The network security device negotiates a session key with any other protected client. Then, all communications between the two clients axe encrypted. The inventive device is self configuring and locks itself to the IP (Internet Protocol) address and MAC (Media Access Control) address of its client. The client cannot change its IP or MAC address once set. Thus, the inventive network security device does not allow a client to emulate another client by setting a false IP or MAC address.
Background of the Invention A. Network Architecture An Internet communications network 100 is depicted in FIG. 1 including five transmit or backbone networks A,B,C,D, and E and three stub networks R, Y, and Z. A "backbone"
network is an intermediary network which conveys communicated data f rom one network to another network . A "stub" network i s a terminal or endpoint network from which communicated data may only initially originate or ultimately be received. Each network, such as the stub network R, includes one or more interconnected subnetworks I, J, L and M. As used herein, the term "subnetwork" refers to a collection of one or more nodes, e.g. , (d) , (a) (b, x, y) , (q, v) (r, z) , (s,u) , (e,f,g),(h,i),(j,k,l),(m,n), and (o,p), interconnected by wires and switches for local internodal communication. Each subnetwork may be a local area network or LAN. Each subnetwork has one or more interconnected nodes which may be host computers ("hosts") u,v,w,x,y,z or routers a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s. A host is an endpoint node from which communicated data my initially originate or ultimately be received. A router is a node which serves solely as an intermediary node between two other nodes; the router receives communicated data from one node and retransmits the data to another node. Collectively, backbone networks, stub networks, subnetworks and nodes are referred to herein as "internet systems".
FIG. 2 shows a block diagram of a host or router node 10.
As shown, the node may include a CPU 11, a memory 12 and one or more I/O ports (or network interfaces) 13-1, 13-2, . . . , 13-N
connected to a bus 14. Illustratively, each I/O port 13-1, 13-2,. . ., 13-N is connected by wires, optical fibers, and/or switches to the I/O port of another node. The I/O ports 13-1, 13-2,. . ., 13-N are for transmitting communicated data in the form of a bitstream organized into one or more packets to another node and for receiving a packet from another node. Ifthe host 10 is a host computer attached to subnetwork which is an Ethernet, then the host will have one I/O port which is an -Ethernet interface.
A host which initially generates a packet for transmission to another node is called the source node and a host wh-ich ultimately receives the packet is called a destination node.
Communication is achieved by transferring packets via a sequence of nodes including the source node, zero or more intermediary nodes, and the destination node, in a bucket brigade fashion.
For example a packet may be communicated from the node-w to the node c, to the node d, to the node b, and to the node x.
An exemplary packet 40 is shown in FIG. 3A having a payload 41 which contains communicated data (i.e., user data) and a header 42 which contains control and/or address information.
Typically, the header information is arranged in layers including an IP layer and a physical layer.
The IP layer typically includes an IP source address, an IP
destination address, a checksum, and a hop count which indicates a number of hops in a multihop network. A physical layer header includes a MAC address (hardware address) of the source and a MAC
address of the destination. ' The user data may include a TCP (Transfer Control Protocol) packet including TCP headers or a UDP (User Data Protocol) packet including UDP headers. These protocols control among other things, the packetizing of information to be transmitted, the reassembly of received packets into the originally transmitted information, and the scheduling of transmission and reception of packets (see e.g., D. Commer, "Internetworking With TCP/IP", Vol. 1 (1991); D. Commer and D. Stevens, "Internetworking With TCP/IP", Vol. 2 (1991)).
In an exemplary Internet protocol call IP, each node of the Internet 100 is assigned an Internet (IP) address which is unique over the entire Internet 100 such as the Internet address for the node y shown in FIG. 3B. See, Information Sciences Institute, RFC 791 "Internet Protocol", September, 1981. The IP addresses are assigned in a hierarchical fashion; the Internet (IP) address of each node contains an address portion 31 indicating the network of the node, an address portion 32 indicating a particular subnetwork of the node, and a host portion 33 which identifies a particular host or router and discriminates between the individual nodes within a particular subnetwork.
In an Internet 100 which uses the IP protocol, the IP
2o addresses of the source and destination nodes are placed in the packet header 42 by the source node. A node which receives a packet can identify the source and destination nodes by examining these addresses.
B. Encryption Techniques Eavesdropping in a network, such as the network 100 of FIG. 1, can be thwarted through the use of a message encryption technique. A message encryption technique employs an encipherment function which utilizes a number referred to as a session key to encipher data (i.e., message content).
Only the pair of hosts in communication with each other have knowledge of the session key, so that only the proper hosts, as paired on a particular conversation, can encrypt and decrypt digital signals. Two examples of encipherment functions are the National Bureau of Standards Data Encryption Standard (DES) (see e.g., National Bureau of Standards, "Data Encryption Standard", FIPS-PUB-45, 1977) and the more recent t~'ast Encipherment Algorithm (FEAL)(see e.g., Shimizu and S.
Miyaguchi, "FEAL-Fast Data Encipherment Algorithm," Systems and Computers in Japan, Vol. 19, No. 7, 1988 and S. Miyaguchi, "The FEAL Cipher Family", Proceedings of CRYPTO '90, Santa Barbara, Calif., Aug., 1990). Another encipherment function is known as IDEA. One way to use an encipherment function is the electronic codebook technique. In this technique a plain text message m is encrypted to produce the cipher text message c using the encipherment function f by the formula c=f(m,sk) where sk is a session key. The message c can only be decrypted with the knowledge of the session key sk to obtain the plain text message m=f (c, sk) .
Session key agreement between two communications hosts may be achieved using public key cryptography. (See e.g., U.S. Patent Nos. 5,222,140, 5,299,263).
Before discussing public key cryptographic techniques, it is useful to provide some background information. Most practical modern cryptography is based on two notorious mathematical problems believed (but not proven) to be hard (i.e., not solvable in polynomial time, on the average). The two problems are known as Factorization and Discrete-Log. The Factorization problem is defined as follows:
Input: N, where N=pq where p and q are large prime numbers Output: p and/or q.
The Discrete-Log problem is defined as follows:
Input : P, g, y, where y=g" mod P, and P is a large prime number Output: x.
(The Discrete-Log problem can be similarly defined with a composite modulus N=pq).
Based on the Factorization and Discrete-Log problems, some other problems have been defined which correspond to the cracking problems of a cryptographic system. ' One system of such a problem which has previously been exploited in cryptography (see, e.g., H.C. Williams, "A
Modification of RSA Public-Key Encryption", IEEE Transactions on lntormation Theory, Vol. IT-26, No. Nov. 6, 1980) is the Modular Square Root problem, which is defined as follows:
Input: N,y, where y-x2 mod N, and N=pg, where p and q are large primes Output: x.
Calculating square roots is easy if p and q are known but hard if p and q are not known. When N is composed of two primes, there are in general four square roots mod N. As used herein, z-_-'fix mod N is defined to mean that x is the smallest l0 integer whereby z2-_x mod N.
Another problem is known as the Composite Diffie-Hellman (CDH) problem, which is defined as follows:
Input : N, g, g" mod N, gy mod N, where N-pq and p and q are large primes.
Output : g"~' mod N .
It has been proven mathematically, that the Modular Square Root and Composite Diffie-Hellman problems are equally difficult to solve as the. above-mentioned factorization problem (see, e.g., M.O. Rabin, "Digitalized Signatures and Public Key Functions as Intractable as Factorization", MIT
Laboratory for Computer Science, TR 212, Jan. 1979; z.
Shmuely, "Composite Diffie-Hellman Public Key Generating Schemes Are Hard To Break", Computer Science Department of Technion, Israel, TR 356, Feb. 1985; and K.S. McCurley, "A
Key Distribution System Equivalent to Factoring:, Journal of Cryptology, Vol. 1, No. 2, 1988, pp. 95-105).
In a typical public-key cryptographic system, each user i has a public key Pi (e.g., a modulus N) and a secret key Si (e.g. , the factors p and q) . A message to user i is encrypted using a public operation which makes use of the public key known to everybody (e. g., squaring a number mod N). However, this message is decrypted using a secret operation (e. g., square root mod N) which makes use of the secret key (e. g., ' the factors p and q).
Field of the Invention The present invention is directed to a network security device that is connected between a protected computer (the client) and a network and a method for utilizing the network security device. The network security device negotiates a session key with any other protected client. Then, all communications between the two clients axe encrypted. The inventive device is self configuring and locks itself to the IP (Internet Protocol) address and MAC (Media Access Control) address of its client. The client cannot change its IP or MAC address once set. Thus, the inventive network security device does not allow a client to emulate another client by setting a false IP or MAC address.
Background of the Invention A. Network Architecture An Internet communications network 100 is depicted in FIG. 1 including five transmit or backbone networks A,B,C,D, and E and three stub networks R, Y, and Z. A "backbone"
network is an intermediary network which conveys communicated data f rom one network to another network . A "stub" network i s a terminal or endpoint network from which communicated data may only initially originate or ultimately be received. Each network, such as the stub network R, includes one or more interconnected subnetworks I, J, L and M. As used herein, the term "subnetwork" refers to a collection of one or more nodes, e.g. , (d) , (a) (b, x, y) , (q, v) (r, z) , (s,u) , (e,f,g),(h,i),(j,k,l),(m,n), and (o,p), interconnected by wires and switches for local internodal communication. Each subnetwork may be a local area network or LAN. Each subnetwork has one or more interconnected nodes which may be host computers ("hosts") u,v,w,x,y,z or routers a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s. A host is an endpoint node from which communicated data my initially originate or ultimately be received. A router is a node which serves solely as an intermediary node between two other nodes; the router receives communicated data from one node and retransmits the data to another node. Collectively, backbone networks, stub networks, subnetworks and nodes are referred to herein as "internet systems".
FIG. 2 shows a block diagram of a host or router node 10.
As shown, the node may include a CPU 11, a memory 12 and one or more I/O ports (or network interfaces) 13-1, 13-2, . . . , 13-N
connected to a bus 14. Illustratively, each I/O port 13-1, 13-2,. . ., 13-N is connected by wires, optical fibers, and/or switches to the I/O port of another node. The I/O ports 13-1, 13-2,. . ., 13-N are for transmitting communicated data in the form of a bitstream organized into one or more packets to another node and for receiving a packet from another node. Ifthe host 10 is a host computer attached to subnetwork which is an Ethernet, then the host will have one I/O port which is an -Ethernet interface.
A host which initially generates a packet for transmission to another node is called the source node and a host wh-ich ultimately receives the packet is called a destination node.
Communication is achieved by transferring packets via a sequence of nodes including the source node, zero or more intermediary nodes, and the destination node, in a bucket brigade fashion.
For example a packet may be communicated from the node-w to the node c, to the node d, to the node b, and to the node x.
An exemplary packet 40 is shown in FIG. 3A having a payload 41 which contains communicated data (i.e., user data) and a header 42 which contains control and/or address information.
Typically, the header information is arranged in layers including an IP layer and a physical layer.
The IP layer typically includes an IP source address, an IP
destination address, a checksum, and a hop count which indicates a number of hops in a multihop network. A physical layer header includes a MAC address (hardware address) of the source and a MAC
address of the destination. ' The user data may include a TCP (Transfer Control Protocol) packet including TCP headers or a UDP (User Data Protocol) packet including UDP headers. These protocols control among other things, the packetizing of information to be transmitted, the reassembly of received packets into the originally transmitted information, and the scheduling of transmission and reception of packets (see e.g., D. Commer, "Internetworking With TCP/IP", Vol. 1 (1991); D. Commer and D. Stevens, "Internetworking With TCP/IP", Vol. 2 (1991)).
In an exemplary Internet protocol call IP, each node of the Internet 100 is assigned an Internet (IP) address which is unique over the entire Internet 100 such as the Internet address for the node y shown in FIG. 3B. See, Information Sciences Institute, RFC 791 "Internet Protocol", September, 1981. The IP addresses are assigned in a hierarchical fashion; the Internet (IP) address of each node contains an address portion 31 indicating the network of the node, an address portion 32 indicating a particular subnetwork of the node, and a host portion 33 which identifies a particular host or router and discriminates between the individual nodes within a particular subnetwork.
In an Internet 100 which uses the IP protocol, the IP
2o addresses of the source and destination nodes are placed in the packet header 42 by the source node. A node which receives a packet can identify the source and destination nodes by examining these addresses.
B. Encryption Techniques Eavesdropping in a network, such as the network 100 of FIG. 1, can be thwarted through the use of a message encryption technique. A message encryption technique employs an encipherment function which utilizes a number referred to as a session key to encipher data (i.e., message content).
Only the pair of hosts in communication with each other have knowledge of the session key, so that only the proper hosts, as paired on a particular conversation, can encrypt and decrypt digital signals. Two examples of encipherment functions are the National Bureau of Standards Data Encryption Standard (DES) (see e.g., National Bureau of Standards, "Data Encryption Standard", FIPS-PUB-45, 1977) and the more recent t~'ast Encipherment Algorithm (FEAL)(see e.g., Shimizu and S.
Miyaguchi, "FEAL-Fast Data Encipherment Algorithm," Systems and Computers in Japan, Vol. 19, No. 7, 1988 and S. Miyaguchi, "The FEAL Cipher Family", Proceedings of CRYPTO '90, Santa Barbara, Calif., Aug., 1990). Another encipherment function is known as IDEA. One way to use an encipherment function is the electronic codebook technique. In this technique a plain text message m is encrypted to produce the cipher text message c using the encipherment function f by the formula c=f(m,sk) where sk is a session key. The message c can only be decrypted with the knowledge of the session key sk to obtain the plain text message m=f (c, sk) .
Session key agreement between two communications hosts may be achieved using public key cryptography. (See e.g., U.S. Patent Nos. 5,222,140, 5,299,263).
Before discussing public key cryptographic techniques, it is useful to provide some background information. Most practical modern cryptography is based on two notorious mathematical problems believed (but not proven) to be hard (i.e., not solvable in polynomial time, on the average). The two problems are known as Factorization and Discrete-Log. The Factorization problem is defined as follows:
Input: N, where N=pq where p and q are large prime numbers Output: p and/or q.
The Discrete-Log problem is defined as follows:
Input : P, g, y, where y=g" mod P, and P is a large prime number Output: x.
(The Discrete-Log problem can be similarly defined with a composite modulus N=pq).
Based on the Factorization and Discrete-Log problems, some other problems have been defined which correspond to the cracking problems of a cryptographic system. ' One system of such a problem which has previously been exploited in cryptography (see, e.g., H.C. Williams, "A
Modification of RSA Public-Key Encryption", IEEE Transactions on lntormation Theory, Vol. IT-26, No. Nov. 6, 1980) is the Modular Square Root problem, which is defined as follows:
Input: N,y, where y-x2 mod N, and N=pg, where p and q are large primes Output: x.
Calculating square roots is easy if p and q are known but hard if p and q are not known. When N is composed of two primes, there are in general four square roots mod N. As used herein, z-_-'fix mod N is defined to mean that x is the smallest l0 integer whereby z2-_x mod N.
Another problem is known as the Composite Diffie-Hellman (CDH) problem, which is defined as follows:
Input : N, g, g" mod N, gy mod N, where N-pq and p and q are large primes.
Output : g"~' mod N .
It has been proven mathematically, that the Modular Square Root and Composite Diffie-Hellman problems are equally difficult to solve as the. above-mentioned factorization problem (see, e.g., M.O. Rabin, "Digitalized Signatures and Public Key Functions as Intractable as Factorization", MIT
Laboratory for Computer Science, TR 212, Jan. 1979; z.
Shmuely, "Composite Diffie-Hellman Public Key Generating Schemes Are Hard To Break", Computer Science Department of Technion, Israel, TR 356, Feb. 1985; and K.S. McCurley, "A
Key Distribution System Equivalent to Factoring:, Journal of Cryptology, Vol. 1, No. 2, 1988, pp. 95-105).
In a typical public-key cryptographic system, each user i has a public key Pi (e.g., a modulus N) and a secret key Si (e.g. , the factors p and q) . A message to user i is encrypted using a public operation which makes use of the public key known to everybody (e. g., squaring a number mod N). However, this message is decrypted using a secret operation (e. g., square root mod N) which makes use of the secret key (e. g., ' the factors p and q).
C. Network Security Devices At present, the existing network security products are categorized into two classes: (1) firewalls, such as Janus and ANS and (2) software products, such as encrypted mail, secured http, one time password, etc. , The firewall is a dedicated computer, usually running a Unix operating system. It acts as a filter for incoming and outgoing communications. The firewall is placed as a router between the local area network (LAN) and the outside world.
The decision whether to pass a packet is made based on the source and/or destination IP address, and the TCP port number.
Some firewalls also have the ability to encrypt data, providing that both sides of the communication employ the same brand of firewall. Some firewalls have a personal authentication feature.
Software products are based on the premise that the computer on which they are installed are secured, and protection is only needed outside on the network. Thus, such software products can easily be bypassed by breaking into the computer. A typical scheme is when an intruder implants a "Trojan Horse" on a computer which sends him an unencrypted copy of every transaction. Sometimes, it is even done as a delayed action during the off-hours when the computer is not likely to be supervised.
In addition, there are authentication products designed to maintain the integrity of the computer against intrusion.
These products are based on the premise that they are 100 0 secured. Once the product is compromised, it becomes totally ineffective. Sometimes, careless use by the one user may jeopardize all other users of the product.
Firewalls are more effective in maintaining network security. However they are very expensive. Their price range is between $10,000 and $50,000, plus the price of the hardware. They require a high level of expertise to install ' and maintain. The most sophisticated and effective firewalls require a specially trained technician or engineer for their maintenance. The special training cost is up to $10,000 per person, and the salary adds $60,000 to $120,000 or more per annum to the cost.
Firewalls have to be constantly maintained, modified, and monitored in order to yield reasonable security. They only cover the TCP part of the Internet Protocol and not the UDP
part. Thus, they do not provide security to NFS (Network File Services) and many client/server applications.
The firewall is a full service computer which can be logged into for maintenance and monitoring. Thus, it can be broken into. Once a firewall is compromised it loses its effectiveness and becomes a liability rather than a security aid. Firewalls only protect the connection between a LAN and a WAN (Wide Area Network). It does not protect against intrusion into a particular host from within the LAN.
In view of the foregoing, it is an object of the present invention to provide a network security device which overcomes the shortcomings of the prior art network security devices.
In particular, i.t is an ob~er_t c~f the nre~ant invani-inn y . _~ __ _- .__. r_____ to provide a hardware device to provide network security for individual hosts attached to a network.
Summary of the Invention The network security device of the present invention comprises a first network interface connected to a protected client, a second network interface connected to a portion of a network, and a processing circuit connected to both interfaces. Illustratively, the portion of the network to which the protected client is connected is an Ethernet and the first and second network interfaces are Ethernet interfaces.
The processing circuit connected in between the two interfaces may be a conventional CPU such as an Intel 486 DX2-66 or a Pentium. Alternatively, the processing circuit may be implemented as one or more ASICs (Application Specific ° Integrated Circuits) or a combination of ASICs and a CPU. A
communication from the protected client, goes from the client, to the first interface, to the processing circuit, to the second interface and into the network. Similarly, a communication received from the network, goes from the second interface, to the processing circuit, to the first interface and to the protected client.
Preferably, the network security device is a sealed device and it cannot be logged into. It has the same IP
address as the protected client.
A number of important functions are performed by the inventive network security device. The network security device learns the MAC and/or IP address of its client and locks itself to these addresses. To lock, the MAC and/or IP
address is stored in a permanent memory of the network security device. A packet arriving from the client will not be passed into the network if the packet has a MAC and/or IP
address different from that which is stored in memory. Thus, the protected client is unable to change its MAC and/or IP
address. This prevents the protected client from emulating the MAC and/or IP address of another client in the network.
When a packet arrives at the first network interface from the client, the processing circuit substitutes a MAC address of the network security device for the MAC address of the protected client. Then the packet is passed to the second interface and into the network. The same translation is performed in reverse for packets arriving at the network security device from the network side.
Packets received from the protected client are encrypted using an encipherment function such as IDEA, FEAL or DES
before being transmitted via the network to a destination.
Similarly encrypted packets received from a destination are decrypted. Such encryption and decryption requires a common session key to be possessed jointly by the protected client and the destination (the destination being a protected client of another network security device located someplace else in the network).
The common session key is obtained using a public key cryptography technique. Thus, both of the protected clients (hereinafter labeled i and j) have public keys Pi, P~ and secret keys Si, S~ . The public keys Pi and P~ have a static CA 02211301 2005-05-13~
part and a dynamic part which is updated periodically. The secret keys Si, S~ also have a static part and a dynamic part., To aid in the key exchange, the network security device maintains two databases. A static database contains information about secured hosts or nodes in the network. A
secured host or node is a host or node that is protected by a network security device. Each entry in the static database contains information about a particular secured host, i.e., the host IP address, time entered in the database, and the l0 host's permanent public key.
A dynamic data base contains information about secured and unsecured hosts. Each entry in the dynamic database includes a host' s IP address, a flag indicating whether or not the host is secured, a flag indicating whether the host is in transition (i.e., in the middle of a key exchange), and a pointer to a common secret session key.
The protocol used by the network security device of host i to agree on a common session key with a network security device of host j is as follows.
Consider a communication from host i to host j. The communication arrives at the network security device of host j from host i. The network security device checks if host j is in the dynamic database. If host j is in the dynamic database, it is determined if the dynamic database has a common session key for communication between host i and host j. If there is such a common session key, the communication from host i is encrypted using the common session key and transmitted to host j. If there is no common session key, then host i sends the dynamic part of its public key P; to host j and host j replies by sending the dynamic part of its public key Pj to host i. The exchange of dynamic parts of the public keys may be encrypted using the static part of the public keys, which may be obtained from the static databases at host i and host j. The common session key is then calculated according to a Diffie-Hellman technique for ' example:
The decision whether to pass a packet is made based on the source and/or destination IP address, and the TCP port number.
Some firewalls also have the ability to encrypt data, providing that both sides of the communication employ the same brand of firewall. Some firewalls have a personal authentication feature.
Software products are based on the premise that the computer on which they are installed are secured, and protection is only needed outside on the network. Thus, such software products can easily be bypassed by breaking into the computer. A typical scheme is when an intruder implants a "Trojan Horse" on a computer which sends him an unencrypted copy of every transaction. Sometimes, it is even done as a delayed action during the off-hours when the computer is not likely to be supervised.
In addition, there are authentication products designed to maintain the integrity of the computer against intrusion.
These products are based on the premise that they are 100 0 secured. Once the product is compromised, it becomes totally ineffective. Sometimes, careless use by the one user may jeopardize all other users of the product.
Firewalls are more effective in maintaining network security. However they are very expensive. Their price range is between $10,000 and $50,000, plus the price of the hardware. They require a high level of expertise to install ' and maintain. The most sophisticated and effective firewalls require a specially trained technician or engineer for their maintenance. The special training cost is up to $10,000 per person, and the salary adds $60,000 to $120,000 or more per annum to the cost.
Firewalls have to be constantly maintained, modified, and monitored in order to yield reasonable security. They only cover the TCP part of the Internet Protocol and not the UDP
part. Thus, they do not provide security to NFS (Network File Services) and many client/server applications.
The firewall is a full service computer which can be logged into for maintenance and monitoring. Thus, it can be broken into. Once a firewall is compromised it loses its effectiveness and becomes a liability rather than a security aid. Firewalls only protect the connection between a LAN and a WAN (Wide Area Network). It does not protect against intrusion into a particular host from within the LAN.
In view of the foregoing, it is an object of the present invention to provide a network security device which overcomes the shortcomings of the prior art network security devices.
In particular, i.t is an ob~er_t c~f the nre~ant invani-inn y . _~ __ _- .__. r_____ to provide a hardware device to provide network security for individual hosts attached to a network.
Summary of the Invention The network security device of the present invention comprises a first network interface connected to a protected client, a second network interface connected to a portion of a network, and a processing circuit connected to both interfaces. Illustratively, the portion of the network to which the protected client is connected is an Ethernet and the first and second network interfaces are Ethernet interfaces.
The processing circuit connected in between the two interfaces may be a conventional CPU such as an Intel 486 DX2-66 or a Pentium. Alternatively, the processing circuit may be implemented as one or more ASICs (Application Specific ° Integrated Circuits) or a combination of ASICs and a CPU. A
communication from the protected client, goes from the client, to the first interface, to the processing circuit, to the second interface and into the network. Similarly, a communication received from the network, goes from the second interface, to the processing circuit, to the first interface and to the protected client.
Preferably, the network security device is a sealed device and it cannot be logged into. It has the same IP
address as the protected client.
A number of important functions are performed by the inventive network security device. The network security device learns the MAC and/or IP address of its client and locks itself to these addresses. To lock, the MAC and/or IP
address is stored in a permanent memory of the network security device. A packet arriving from the client will not be passed into the network if the packet has a MAC and/or IP
address different from that which is stored in memory. Thus, the protected client is unable to change its MAC and/or IP
address. This prevents the protected client from emulating the MAC and/or IP address of another client in the network.
When a packet arrives at the first network interface from the client, the processing circuit substitutes a MAC address of the network security device for the MAC address of the protected client. Then the packet is passed to the second interface and into the network. The same translation is performed in reverse for packets arriving at the network security device from the network side.
Packets received from the protected client are encrypted using an encipherment function such as IDEA, FEAL or DES
before being transmitted via the network to a destination.
Similarly encrypted packets received from a destination are decrypted. Such encryption and decryption requires a common session key to be possessed jointly by the protected client and the destination (the destination being a protected client of another network security device located someplace else in the network).
The common session key is obtained using a public key cryptography technique. Thus, both of the protected clients (hereinafter labeled i and j) have public keys Pi, P~ and secret keys Si, S~ . The public keys Pi and P~ have a static CA 02211301 2005-05-13~
part and a dynamic part which is updated periodically. The secret keys Si, S~ also have a static part and a dynamic part., To aid in the key exchange, the network security device maintains two databases. A static database contains information about secured hosts or nodes in the network. A
secured host or node is a host or node that is protected by a network security device. Each entry in the static database contains information about a particular secured host, i.e., the host IP address, time entered in the database, and the l0 host's permanent public key.
A dynamic data base contains information about secured and unsecured hosts. Each entry in the dynamic database includes a host' s IP address, a flag indicating whether or not the host is secured, a flag indicating whether the host is in transition (i.e., in the middle of a key exchange), and a pointer to a common secret session key.
The protocol used by the network security device of host i to agree on a common session key with a network security device of host j is as follows.
Consider a communication from host i to host j. The communication arrives at the network security device of host j from host i. The network security device checks if host j is in the dynamic database. If host j is in the dynamic database, it is determined if the dynamic database has a common session key for communication between host i and host j. If there is such a common session key, the communication from host i is encrypted using the common session key and transmitted to host j. If there is no common session key, then host i sends the dynamic part of its public key P; to host j and host j replies by sending the dynamic part of its public key Pj to host i. The exchange of dynamic parts of the public keys may be encrypted using the static part of the public keys, which may be obtained from the static databases at host i and host j. The common session key is then calculated according to a Diffie-Hellman technique for ' example:
Assume that Pi _ gsi mod N where N is either prime or the product of two primes. Assume that P~ - gs~ mod N. After the exchange of public keys, the network security device at host i calculates r~ _ p~ s~ _ g s~s~ mod N. Similarly, the network security device at host j calculated rJ _ piss - g s~s~ mod N.
Thus, both hosts i and j are in possession of the same number r~. This number may then be used as a common session key or used to derive a common session key.
Note that this assumes that there is an entry for host j in the static database of host i. If there is not, the exchange of dynamic public keys is preceded by an exchange of static public keys and the forming of a database entry for host j in the static database at host i. Moreover, if there is no entry for host j in the dynamic database of host i, such an entry will be generated before the dynamic key exchange.
It should be noted that encryption takes place at the IP
level so that TCP and UDP packets are encoded.
In short, the inventive network security device has a number of significant advantages.
Like a firewall, the inventive network security device is a hardware/software combination in a preferred implementation.
However, it is a sealed ~~box~~ and cannot be logged into.
Hence, it cannot be compromised the way a firewall can. It is much cheaper than a firewall. Thus, each node in the LAN can be equipped with it. This way, it provides protection inside the LAN as well as outside. The network security device works directly at the IP level. It therefore, covers all types of IP protocols and requires no special configuration to different network applications. Thus, the inventive network security device is maintenance free.
The inventive network security device senses the IP
address of the client host and locks itself to it: It requires no installation. Once locked, it does not allow the client host to change its IP address. The inventive network security device also maintains a permanent database of secured hosts. If a request for key arbitration arrives that conflicts with the database, that host is denied communication. The combination of the above two features creates a double authentication of the IP address. The inventive security device creates a physical barrier between the client and the network. Thus, preventing attempts to _ 5 bypass by direct Ethernet communications.
The inventive security device encrypts all communication to the network, including the exchange of dynamic public keys.
Brief Description of the Drawings FIG 1 schematically illustrates an Internet network.
to FIG 2 schematically illustrates the architecture of a host in the network of FIG 1.
FIGS 3A and 3B illustrate the format of a packet transmitted in the network of FIG 1.
15 FIG 4 illustrates a network security device for use with a host in the network of FIG 1 in accordance with an embodiment of the present invention.
FIG 5 illustrates an entry in a ~rar;r~ ~araha~A
___ __ __...___ ,_ maintained by the network security device of FIG 4.
20 FIG 6 illustrates an entry in a dynamic database maintained by the network security device of FIG 4.
FIG 7 is a flow chart which illustrates a key exchange algorithm utilized by the network security device of FIG 4.
FIG 8 is a flow chart of an ARP handling algorithm 25 utilized by the network security device of FIG 4.
FIG 9 is a flow chart of an IP packet handling algorithm utilized by the network security device of FIG 4.
Tlcta i l or7 Tlee.~"..~ ~,+-~ .~. ...~ ~1... r__-__~ _ r.v~ arcw.r..a.~m.ivit yt 1~11C .111VCIlLIOIl 30 FIG 4 schematically illustrates a network security device in accordance with an illustrative embodiment of the invention. The security device 10 comprises a first interface 0 which is connected to the client host 12. Specifically, the ' interface 0 is connected to a network interface in the client 35 host 12 (e. g., an interface 13 of Fig. 2) via a cable or wire 13. The security device 10 comprises a second interface 1 which is connected to a portion of a network 100.
Illustratively, the interface 1 is connected to an Ethernet so that the interfaces 0, 1 are Ethernet interfaces such as SMC
Elite Ultra Interfaces.
A CPU 14 is connected to the interfaces 0,1. The CPU is for example an Intel 486 DX 62-66. A static memory 16 (e.g.
flash EEPROM) is connected to the CPU 14 and a dynamic memory 18 (e.g. RAM) is connected to the CPU 14. An optional encryption module 20 performs encryption and large number arithmetic operations. The encryption unit may be implemented as a programmable logic array. Alternatively, the encryption module may be omitted and its function may be carried out using a software program which is executed by the CPU 14. The interface 0 is put in a promiscuous mode. In this mode, the interface 0 passes all communications from the client host 12 that is sensed on the cable 13 to the CPU 14. - The network connection is via the interface-1 which is set to the same IP
address as the client 12. The network security device 10 responds to the Address Resolution Protocol by sending its own (rather than the client's) MAC address. This adds a level of security by blocking attempts to bypass the device 10 using the Ethernet protocol.
The CPU 14 maintains two databases. One database is a static database stored in the Flash ROM 16. This database contains permanent information- about secured nodes in the network, i.e., the node IP address, time entered into the database, the nodes permanent public key. The structure of an illustrative record for a node in this database is shown in FIG 5.
A second database is a dynamic database. The dynamic database contains information about secured and unsecured nodes, i.e., the node IP address, time last updated, a flag indicating whether the node is secured (e.g.,has its own network security device), a flag indicating whether the node is in transition (i.e., in the middle of a key exchange), a ' pointer to a common secret key with that node. The structure of an illustrative record for a node in this database is shown ' in FIG 6. The transition flag has three possible values, 0-~CA 02211301 2005-05-13 not in transition, 1-pending reply from remote host, and 2-pending computation of common key.
The software executed by the CPU 14 has three components (1) operating system, (2) networking system, (3) key computation ,algorithms. The operating system and the networking system are both part of a Unix like kernel. The key computation algorithms reside in memory and are signalled into action by the networking system. The operating system is a lobotomized Linux system with all drivers taken out except to the R.AM, disk and Ethernet interfaces. The networking system is for communication, key exchange, encryption, configuration, etc.
The key exchange algorithm is illustrated in Fig. 7.
Consider the case where the host client wants to send a communication to a node in the network whose IP = A. when the communication arrives at the network security device of the host client (step 60 of Fig. 6), the dynamic data base (DDB) is checked to determine if there is an entry for node A in the dynamic data base (step 61). If there is an entry for node A
in the dynamic data base, a check is made to see if a common session key for node A and the protected client has expired (step 62).
If the common session key has not expired the packet is encrypted using the session key and an encipherment function such as IDEA (step 63). If the common session key has expired, the dynamic data base entry for the node IP=A is marked in unsecured transition (step 64) which means a key exchange is taking place.
The exchange of the dynamic parts of the public keys of 3o the host client and the node with IP=A proceeds as follows.
The host client (i.e., the source) sends its dynamic public key and IP address to the node with IP=A (the destination) (step 65) and waits five seconds for a reply (step 66). The ' dynamic public key of the host may be encrypted with the static public key of the node with IP=A. The reply is the ' dynamic public key of the destination node with IP=A. This may be encrypted with the .static public key of the host client. The steps 65 and 66 are repeated three times. If no reply is received (step 68) from the destination, the source network security device marks the transition off (step 67) in the DDB entry for the destination.
If a reply is received the transition flag for the -destination in the DDB of the network security device of the host is set to 2 (step 69). Then a common session key for the source and destination is calculated by the network security device ofthe source (step 70) using for example a Diffie-Hellman technique as described above. The common session key is then entered into the DDB of the source network security device (step 71) and the transition flag for this DDB entry is marked 0 (step 72).
The exchange of dynamic public keys and the calculation of a common session assumes that there is an entry for the destination node with IP=A in the static data base (SDB) of the source network security device and in the dynamic data base of the source network security device. If these entries do not exist, they may be created prior to dynamic public key exchange (steps 65-69).
If there is no DDB entry for node IP=A, (step 61) an entry is created (step 81) and the transition flag for this entry is marked in unsecured transition (step 82). A check is then made to determine if the SDB of the source network security device has an entry for node IP=A (step 83). If there is such an entry, proceed with dynamic key exchange (step 65 etc.). The source network security device transmits the permanent public key of the source to node IP=A (step 84) and waits five seconds for a reply (step 85) . The steps 84 and 85 may be repeated several, e.g., three times.
If a reply is received (step 86), an entry is created in the SDB (step 87). If no reply is received, the transition flag in the entry in the DDB is marked transition off(step 67) . .
As indicated above in a preferred embodiment, the network security device is a sealed box which cannot be logged into.
The network security device 10 senses the IP _(and/or MAC) _ ... _ . ., _ .. _CA 02211301 2005-05-13 _ .... .._. ....___. _ WO 97/13340 PCT/rJS96/14285 address of the client host 12 and locks itself to it. once the network security device is locked to the address, the client is prevented by the network security device from changing its IP (and/or MAC) address.
_ 5 The Address Resolution Protocol (ARP) is the protocol which is used to resolve an IP address into a matching ,, Ethernet machine (MAC) address which is the actual address to which the network interface responds.
The inventive network security device uses ARP (Address Resolution Protocol) to configure itself and hide the client host.
Fig. 8 Shows how the inventive network security device processes an ARP request with IP=B. The request may arrive from the host at interface 0 or form the network at interface 1 (step 100) . If the request arrives via interface 0, the network security device determines if it is configured tstep 102). If the network security device is not configured, it configures itself (step 103). Configuration involves storing in a permanent memory, the IP address and/or the MAC address of the host. After configuration, the CPU in the network security device replaces the MAC address of the source with the MAC address of interface 1 (step 104) and sends the request to interface 1 (step 105). The request is then transmitted to its destination. via the network.
If the host's network security device is already configured (step 102), it is determined if the request is a reply (step 106) . This is done by checking the destination MAC field. In a reply this field is not zero. If the request is not a reply, MAC address translation takes place according to step 104 and the request is sent to interface 1 (step 105) for transmission into the network. If the request is a reply, it is determined if the source IP address in the request matches the IP address now permanently stored in memory (step ' 107). If there is a match, the request is dropped (step 108) since the network security device has already answered the ' ARP. If there is not a match, the system is shut down (step 109) .
It the request arrives via the network at interface 1, the request is passed to interface 0 (step 111). If the request is a reply (step 112), pass the request to the interface 0 (step 113). If the request is not a reply, the request is answered using the MAC address of interface 1 (step 114 ) .
Fig. 9 illustrates a packet handling algorithm utilized by the inventive network security device. Illustratively the packet arrives with the source address IP=C (step 200). The packet may arrive from the host at interface 0 from the network at interface 1.
First consider the case where the packet arrives from the host at interface 0. If the packet carries an ICMP (Internet Control Message Protocol) or IGMP (Internet Gateway Message Protocol) identification (step 201), the packet is passed to the interface 1 without encryption. However, the source MAC
address in the packet is translated to the MAC address of interface 1 (step 202). ICMP and IGMP Packets are not addressed to a destination host. Rather these packets are utilized by intermediate entities in the network, e.g., routers, for various functions.
If the destination to which the packet is addressed is insecure, the packet is dropped (step 203, 204). The device may be in a secured/unsecured mode (special order). In such case the packet will be sent unchanged.
Next, it is determined if the packet contains a part of a message that has been fragmented (step 205). If the packet contains a fragment, the fragments are collected (step 206) and the message is encrypted (step 207). The encryption takes place using the common session key and an -encipherment function. If the encrypted message is too long for the particular LAN (step 208), it is fragmented (step 209). An encrypted packet is then transmitted to interface 1 for transmission into the network (step 210). ' An encrypted packet carries a signature in the protocol IS part of the IP header. This indicates that the packet is encrypted. The IP address of a packet is not encrypted, ._.;. _.___ __ _- ._.. . . __... .-. ..-._~_. CA 02211301 2005-05-13-=--... __ _.... .._._....
otherwise the packet could not be routed through the network.
The case where the packet arrives via the network at interface 1 is now considered. If the packet is an ICMP or IGMP packet (step 220) no decryption is necessary and the - 5 packet is sent to interface 0 (step 221). If the packet is a key exchange packet (step 222) the packet is processed according to the key exchange protocol (step 223). If the packet is not encrypted (step 224) the packet is dropped (step 225). The device may be in a secured/unsecured mode (special l0 order) . In such cases the packet will be sent to the client unchanged. If the packet is encrypted but the network security device does not have the key (step 226), the key exchange protocol is carried out (step 227) and the packet is dropped (step 228). If the key is available in the dynamic 15 data base of the network security device, the packet is decrypted (step 229) and sent to interface 0 (step 230).
For packets received from the network the MAC address of the network security device is translated into the MAC address of the client. For packets received from the protected 20 client, the MAC address of the client is translated into the MAC address of the network security device.
In short, a unique network security device has been disclosed. Finally, the above described embodiments of the invention are intended to be illustrative. only. Numerous 25 alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
Thus, both hosts i and j are in possession of the same number r~. This number may then be used as a common session key or used to derive a common session key.
Note that this assumes that there is an entry for host j in the static database of host i. If there is not, the exchange of dynamic public keys is preceded by an exchange of static public keys and the forming of a database entry for host j in the static database at host i. Moreover, if there is no entry for host j in the dynamic database of host i, such an entry will be generated before the dynamic key exchange.
It should be noted that encryption takes place at the IP
level so that TCP and UDP packets are encoded.
In short, the inventive network security device has a number of significant advantages.
Like a firewall, the inventive network security device is a hardware/software combination in a preferred implementation.
However, it is a sealed ~~box~~ and cannot be logged into.
Hence, it cannot be compromised the way a firewall can. It is much cheaper than a firewall. Thus, each node in the LAN can be equipped with it. This way, it provides protection inside the LAN as well as outside. The network security device works directly at the IP level. It therefore, covers all types of IP protocols and requires no special configuration to different network applications. Thus, the inventive network security device is maintenance free.
The inventive network security device senses the IP
address of the client host and locks itself to it: It requires no installation. Once locked, it does not allow the client host to change its IP address. The inventive network security device also maintains a permanent database of secured hosts. If a request for key arbitration arrives that conflicts with the database, that host is denied communication. The combination of the above two features creates a double authentication of the IP address. The inventive security device creates a physical barrier between the client and the network. Thus, preventing attempts to _ 5 bypass by direct Ethernet communications.
The inventive security device encrypts all communication to the network, including the exchange of dynamic public keys.
Brief Description of the Drawings FIG 1 schematically illustrates an Internet network.
to FIG 2 schematically illustrates the architecture of a host in the network of FIG 1.
FIGS 3A and 3B illustrate the format of a packet transmitted in the network of FIG 1.
15 FIG 4 illustrates a network security device for use with a host in the network of FIG 1 in accordance with an embodiment of the present invention.
FIG 5 illustrates an entry in a ~rar;r~ ~araha~A
___ __ __...___ ,_ maintained by the network security device of FIG 4.
20 FIG 6 illustrates an entry in a dynamic database maintained by the network security device of FIG 4.
FIG 7 is a flow chart which illustrates a key exchange algorithm utilized by the network security device of FIG 4.
FIG 8 is a flow chart of an ARP handling algorithm 25 utilized by the network security device of FIG 4.
FIG 9 is a flow chart of an IP packet handling algorithm utilized by the network security device of FIG 4.
Tlcta i l or7 Tlee.~"..~ ~,+-~ .~. ...~ ~1... r__-__~ _ r.v~ arcw.r..a.~m.ivit yt 1~11C .111VCIlLIOIl 30 FIG 4 schematically illustrates a network security device in accordance with an illustrative embodiment of the invention. The security device 10 comprises a first interface 0 which is connected to the client host 12. Specifically, the ' interface 0 is connected to a network interface in the client 35 host 12 (e. g., an interface 13 of Fig. 2) via a cable or wire 13. The security device 10 comprises a second interface 1 which is connected to a portion of a network 100.
Illustratively, the interface 1 is connected to an Ethernet so that the interfaces 0, 1 are Ethernet interfaces such as SMC
Elite Ultra Interfaces.
A CPU 14 is connected to the interfaces 0,1. The CPU is for example an Intel 486 DX 62-66. A static memory 16 (e.g.
flash EEPROM) is connected to the CPU 14 and a dynamic memory 18 (e.g. RAM) is connected to the CPU 14. An optional encryption module 20 performs encryption and large number arithmetic operations. The encryption unit may be implemented as a programmable logic array. Alternatively, the encryption module may be omitted and its function may be carried out using a software program which is executed by the CPU 14. The interface 0 is put in a promiscuous mode. In this mode, the interface 0 passes all communications from the client host 12 that is sensed on the cable 13 to the CPU 14. - The network connection is via the interface-1 which is set to the same IP
address as the client 12. The network security device 10 responds to the Address Resolution Protocol by sending its own (rather than the client's) MAC address. This adds a level of security by blocking attempts to bypass the device 10 using the Ethernet protocol.
The CPU 14 maintains two databases. One database is a static database stored in the Flash ROM 16. This database contains permanent information- about secured nodes in the network, i.e., the node IP address, time entered into the database, the nodes permanent public key. The structure of an illustrative record for a node in this database is shown in FIG 5.
A second database is a dynamic database. The dynamic database contains information about secured and unsecured nodes, i.e., the node IP address, time last updated, a flag indicating whether the node is secured (e.g.,has its own network security device), a flag indicating whether the node is in transition (i.e., in the middle of a key exchange), a ' pointer to a common secret key with that node. The structure of an illustrative record for a node in this database is shown ' in FIG 6. The transition flag has three possible values, 0-~CA 02211301 2005-05-13 not in transition, 1-pending reply from remote host, and 2-pending computation of common key.
The software executed by the CPU 14 has three components (1) operating system, (2) networking system, (3) key computation ,algorithms. The operating system and the networking system are both part of a Unix like kernel. The key computation algorithms reside in memory and are signalled into action by the networking system. The operating system is a lobotomized Linux system with all drivers taken out except to the R.AM, disk and Ethernet interfaces. The networking system is for communication, key exchange, encryption, configuration, etc.
The key exchange algorithm is illustrated in Fig. 7.
Consider the case where the host client wants to send a communication to a node in the network whose IP = A. when the communication arrives at the network security device of the host client (step 60 of Fig. 6), the dynamic data base (DDB) is checked to determine if there is an entry for node A in the dynamic data base (step 61). If there is an entry for node A
in the dynamic data base, a check is made to see if a common session key for node A and the protected client has expired (step 62).
If the common session key has not expired the packet is encrypted using the session key and an encipherment function such as IDEA (step 63). If the common session key has expired, the dynamic data base entry for the node IP=A is marked in unsecured transition (step 64) which means a key exchange is taking place.
The exchange of the dynamic parts of the public keys of 3o the host client and the node with IP=A proceeds as follows.
The host client (i.e., the source) sends its dynamic public key and IP address to the node with IP=A (the destination) (step 65) and waits five seconds for a reply (step 66). The ' dynamic public key of the host may be encrypted with the static public key of the node with IP=A. The reply is the ' dynamic public key of the destination node with IP=A. This may be encrypted with the .static public key of the host client. The steps 65 and 66 are repeated three times. If no reply is received (step 68) from the destination, the source network security device marks the transition off (step 67) in the DDB entry for the destination.
If a reply is received the transition flag for the -destination in the DDB of the network security device of the host is set to 2 (step 69). Then a common session key for the source and destination is calculated by the network security device ofthe source (step 70) using for example a Diffie-Hellman technique as described above. The common session key is then entered into the DDB of the source network security device (step 71) and the transition flag for this DDB entry is marked 0 (step 72).
The exchange of dynamic public keys and the calculation of a common session assumes that there is an entry for the destination node with IP=A in the static data base (SDB) of the source network security device and in the dynamic data base of the source network security device. If these entries do not exist, they may be created prior to dynamic public key exchange (steps 65-69).
If there is no DDB entry for node IP=A, (step 61) an entry is created (step 81) and the transition flag for this entry is marked in unsecured transition (step 82). A check is then made to determine if the SDB of the source network security device has an entry for node IP=A (step 83). If there is such an entry, proceed with dynamic key exchange (step 65 etc.). The source network security device transmits the permanent public key of the source to node IP=A (step 84) and waits five seconds for a reply (step 85) . The steps 84 and 85 may be repeated several, e.g., three times.
If a reply is received (step 86), an entry is created in the SDB (step 87). If no reply is received, the transition flag in the entry in the DDB is marked transition off(step 67) . .
As indicated above in a preferred embodiment, the network security device is a sealed box which cannot be logged into.
The network security device 10 senses the IP _(and/or MAC) _ ... _ . ., _ .. _CA 02211301 2005-05-13 _ .... .._. ....___. _ WO 97/13340 PCT/rJS96/14285 address of the client host 12 and locks itself to it. once the network security device is locked to the address, the client is prevented by the network security device from changing its IP (and/or MAC) address.
_ 5 The Address Resolution Protocol (ARP) is the protocol which is used to resolve an IP address into a matching ,, Ethernet machine (MAC) address which is the actual address to which the network interface responds.
The inventive network security device uses ARP (Address Resolution Protocol) to configure itself and hide the client host.
Fig. 8 Shows how the inventive network security device processes an ARP request with IP=B. The request may arrive from the host at interface 0 or form the network at interface 1 (step 100) . If the request arrives via interface 0, the network security device determines if it is configured tstep 102). If the network security device is not configured, it configures itself (step 103). Configuration involves storing in a permanent memory, the IP address and/or the MAC address of the host. After configuration, the CPU in the network security device replaces the MAC address of the source with the MAC address of interface 1 (step 104) and sends the request to interface 1 (step 105). The request is then transmitted to its destination. via the network.
If the host's network security device is already configured (step 102), it is determined if the request is a reply (step 106) . This is done by checking the destination MAC field. In a reply this field is not zero. If the request is not a reply, MAC address translation takes place according to step 104 and the request is sent to interface 1 (step 105) for transmission into the network. If the request is a reply, it is determined if the source IP address in the request matches the IP address now permanently stored in memory (step ' 107). If there is a match, the request is dropped (step 108) since the network security device has already answered the ' ARP. If there is not a match, the system is shut down (step 109) .
It the request arrives via the network at interface 1, the request is passed to interface 0 (step 111). If the request is a reply (step 112), pass the request to the interface 0 (step 113). If the request is not a reply, the request is answered using the MAC address of interface 1 (step 114 ) .
Fig. 9 illustrates a packet handling algorithm utilized by the inventive network security device. Illustratively the packet arrives with the source address IP=C (step 200). The packet may arrive from the host at interface 0 from the network at interface 1.
First consider the case where the packet arrives from the host at interface 0. If the packet carries an ICMP (Internet Control Message Protocol) or IGMP (Internet Gateway Message Protocol) identification (step 201), the packet is passed to the interface 1 without encryption. However, the source MAC
address in the packet is translated to the MAC address of interface 1 (step 202). ICMP and IGMP Packets are not addressed to a destination host. Rather these packets are utilized by intermediate entities in the network, e.g., routers, for various functions.
If the destination to which the packet is addressed is insecure, the packet is dropped (step 203, 204). The device may be in a secured/unsecured mode (special order). In such case the packet will be sent unchanged.
Next, it is determined if the packet contains a part of a message that has been fragmented (step 205). If the packet contains a fragment, the fragments are collected (step 206) and the message is encrypted (step 207). The encryption takes place using the common session key and an -encipherment function. If the encrypted message is too long for the particular LAN (step 208), it is fragmented (step 209). An encrypted packet is then transmitted to interface 1 for transmission into the network (step 210). ' An encrypted packet carries a signature in the protocol IS part of the IP header. This indicates that the packet is encrypted. The IP address of a packet is not encrypted, ._.;. _.___ __ _- ._.. . . __... .-. ..-._~_. CA 02211301 2005-05-13-=--... __ _.... .._._....
otherwise the packet could not be routed through the network.
The case where the packet arrives via the network at interface 1 is now considered. If the packet is an ICMP or IGMP packet (step 220) no decryption is necessary and the - 5 packet is sent to interface 0 (step 221). If the packet is a key exchange packet (step 222) the packet is processed according to the key exchange protocol (step 223). If the packet is not encrypted (step 224) the packet is dropped (step 225). The device may be in a secured/unsecured mode (special l0 order) . In such cases the packet will be sent to the client unchanged. If the packet is encrypted but the network security device does not have the key (step 226), the key exchange protocol is carried out (step 227) and the packet is dropped (step 228). If the key is available in the dynamic 15 data base of the network security device, the packet is decrypted (step 229) and sent to interface 0 (step 230).
For packets received from the network the MAC address of the network security device is translated into the MAC address of the client. For packets received from the protected 20 client, the MAC address of the client is translated into the MAC address of the network security device.
In short, a unique network security device has been disclosed. Finally, the above described embodiments of the invention are intended to be illustrative. only. Numerous 25 alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
Claims (27)
1. A network security device for protecting at least one particular node which communicates via a network comprising:
(a) a first network interface connected to the at least one particular node and having a first MAC (Media Access Control) address, (b) a second network interface connected to the network and having a second MAC address, (c) a processing circuit connected to said first and second interfaces, said processing circuit configured to:
(1) for a packet received at the first network interface having a header containing a source IP (Internet Protocol) address and a source address corresponding to the first MAC address of the at least one particular node, changing the header by replacing the first MAC address with the second MAC
address without changing the source IP address before said received packet is transmitted into said network by said second interface, and (2) for a packet received at the second network interface having a header containing a destination IP address identifying the at least one particular node and the second MAC
address, changing the header by replacing the second MAC address with the first MAC address without changing the destination IP
address.
(a) a first network interface connected to the at least one particular node and having a first MAC (Media Access Control) address, (b) a second network interface connected to the network and having a second MAC address, (c) a processing circuit connected to said first and second interfaces, said processing circuit configured to:
(1) for a packet received at the first network interface having a header containing a source IP (Internet Protocol) address and a source address corresponding to the first MAC address of the at least one particular node, changing the header by replacing the first MAC address with the second MAC
address without changing the source IP address before said received packet is transmitted into said network by said second interface, and (2) for a packet received at the second network interface having a header containing a destination IP address identifying the at least one particular node and the second MAC
address, changing the header by replacing the second MAC address with the first MAC address without changing the destination IP
address.
2. The network security device of claim 1, wherein said first and second network interfaces are Ethernet interfaces.
3. The network security devices of claim 1, wherein said processing circuit encrypts user data contained in said packet received from said at least one particular node, while an IP
address contained in said packet received from said at least one particular node remains unencrypted.
address contained in said packet received from said at least one particular node remains unencrypted.
4. The network security device of claim 3, wherein said processing circuit encrypts a TCP (Transfer Control Protocol) packet including a TCP packet header contained in said packet received from said at least one particular node.
5. The network security device of claim 3, wherein said processing circuit encrypts a UDP (User Data Protocol) packet including a UDP packet header contained in said packet received from said at least one particular node.
6. The network security device of claim 3, wherein said processing circuit encrypts said user data using a session key and an encipherment function.
7. The network security device of claim 1, wherein said network security device maintains a first database containing information indicating a first IP address and a permanent public key for one or more nodes in said network.
8. The network security device of claim 7, wherein said network security device maintains a second database indicating for one or more nodes in said network, a second IP address, and a common session key with said at least one particular node.
9. The network security device of claim 8, wherein said one or more nodes in said second database are unsecured nodes.
10. A network security device for protecting at least one particular node which communicates via a network comprising:
a first network interface connected to said at least one particular node, a second network interface connected to said network, and a processing circuit connected to said first and second interfaces, said processing circuit encrypting user data contained in a packet received at said first interface from said at least one particular node before said packet is transmitted by said second interface into said network, while an IP address in said packet remains unencrypted.
a first network interface connected to said at least one particular node, a second network interface connected to said network, and a processing circuit connected to said first and second interfaces, said processing circuit encrypting user data contained in a packet received at said first interface from said at least one particular node before said packet is transmitted by said second interface into said network, while an IP address in said packet remains unencrypted.
11. The network security device of claim 10, wherein said user data is a TCP packet.
12. The network security device of claim 10, wherein said user data is a UDP packet.
13. The network security device of claim 10, wherein said processing circuit translates a first MAC address of said at least one particular node contained in said packet into a second MAC
address of said network security device.
address of said network security device.
14. A method for transmitting a packet from a first node into a network comprising the steps of:
(1) generating said packet having a header containing a first source MAC address of said first node, an IP address of a destination, and user data, (2) in a network security device connected between said first node and said network, modifying the header by replacing the first source MAC address of said first node with a second MAC address associated with the network security device without changing the IP
address of the destination, and (3) transmitting said packet into said network.
(1) generating said packet having a header containing a first source MAC address of said first node, an IP address of a destination, and user data, (2) in a network security device connected between said first node and said network, modifying the header by replacing the first source MAC address of said first node with a second MAC address associated with the network security device without changing the IP
address of the destination, and (3) transmitting said packet into said network.
15. The method of claim 14 further comprising the step of in said network security device encrypting said user data, while leaving said IP address unencrypted.
16. The method of claim 14, wherein said user data includes a TCP
packet.
packet.
17. The method of claim 14, wherein said user data includes a UTP
packet.
packet.
18. The method of claim 15, wherein said encrypting step comprises negotiating a session key common to said first node and a second node in said network.
19. The method of claim 18, wherein said step of negotiating a common session key comprises the steps of:
(1) at said network security device, using a static public key of said second node, encrypting a dynamic public key of said first node and transmitting said dynamic public key of said first node to said second node, (2) receiving from said second node a dynamic public key of said second node encrypted with a static public key of said first node and decrypting said dynamic public key of said second node with a static secret key of said first node at said network security device, (3) at said network security device, generating said common session key from a dynamic secret key of said first host and said dynamic public key of said second node.
(1) at said network security device, using a static public key of said second node, encrypting a dynamic public key of said first node and transmitting said dynamic public key of said first node to said second node, (2) receiving from said second node a dynamic public key of said second node encrypted with a static public key of said first node and decrypting said dynamic public key of said second node with a static secret key of said first node at said network security device, (3) at said network security device, generating said common session key from a dynamic secret key of said first host and said dynamic public key of said second node.
20. The method of claim 19, wherein said first node maintains a static database containing information which identifies static public keys of other nodes in said network and from which said network security device obtains said static public key of said second node.
21. The method of claim 20, wherein said network security device maintains a dynamic database including an indicator of said common session key.
22. A method for transmitting a packet from a node into a network comprising the steps of:
(1) generating a packet containing a MAC address of said host, an IP address of a destination, and user data, (2) in a network security device connected between said host and said network, encrypting said user data but not said IP
address, (3) transmitting said packet into said network.
(1) generating a packet containing a MAC address of said host, an IP address of a destination, and user data, (2) in a network security device connected between said host and said network, encrypting said user data but not said IP
address, (3) transmitting said packet into said network.
23. In combination, a node in a network, and a security device connected between said node and said network, said security device preventing said node from transmitted packets to said network if the IP address of said node has changed so that said node cannot emulate another node in said network.
24. The combination of claim 23, wherein said security device stores said IP address in a permanent memory and blocks packets received from said node with second IP address different from said stored IP address from entering said network.
25. The combination of claim 23, wherein said security device comprises a first network interface connected to said node, a second network interface connected to said network, and a processing circuit connected to said first and second interfaces for encrypting user data but not IP addresses.
26. A method for preventing a node in a network from emulating another node in said network comprising the steps of:
(1) in a memory in a network security device connected between said node and said network, permanently storing a characteristic address of said node, (2) receiving a source address contained in a packet received from said node by said security device and composing said source address with said characteristic address permanently stored, (3) using said network security device to block packets received at said network security device from said node with a source address different from the permanently stored address from entering said network.
(1) in a memory in a network security device connected between said node and said network, permanently storing a characteristic address of said node, (2) receiving a source address contained in a packet received from said node by said security device and composing said source address with said characteristic address permanently stored, (3) using said network security device to block packets received at said network security device from said node with a source address different from the permanently stored address from entering said network.
27. The method of claim 26, wherein said characteristic address is an IP address or a MAC address.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/529,497 US5757924A (en) | 1995-09-18 | 1995-09-18 | Network security device which performs MAC address translation without affecting the IP address |
US08/529,497 | 1995-09-18 | ||
PCT/US1996/014285 WO1997013340A1 (en) | 1995-09-18 | 1996-09-06 | Network security device |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2211301A1 CA2211301A1 (en) | 1997-04-10 |
CA2211301C true CA2211301C (en) | 2006-01-24 |
Family
ID=24110154
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002211301A Expired - Fee Related CA2211301C (en) | 1995-09-18 | 1996-09-06 | Network security device |
Country Status (8)
Country | Link |
---|---|
US (2) | US5757924A (en) |
EP (1) | EP0872074A1 (en) |
CN (1) | CN1173256A (en) |
AU (1) | AU725712B2 (en) |
CA (1) | CA2211301C (en) |
IL (1) | IL121416A (en) |
SG (2) | SG96185A1 (en) |
WO (1) | WO1997013340A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11122054B2 (en) | 2019-08-27 | 2021-09-14 | Bank Of America Corporation | Security tool |
Families Citing this family (209)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7702540B1 (en) * | 1995-04-26 | 2010-04-20 | Ebay Inc. | Computer-implement method and system for conducting auctions on the internet |
US7937312B1 (en) | 1995-04-26 | 2011-05-03 | Ebay Inc. | Facilitating electronic commerce transactions through binding offers |
US5793763A (en) * | 1995-11-03 | 1998-08-11 | Cisco Technology, Inc. | Security system for network address translation systems |
US7113508B1 (en) * | 1995-11-03 | 2006-09-26 | Cisco Technology, Inc. | Security system for network address translation systems |
US5918018A (en) * | 1996-02-09 | 1999-06-29 | Secure Computing Corporation | System and method for achieving network separation |
US5867647A (en) * | 1996-02-09 | 1999-02-02 | Secure Computing Corporation | System and method for securing compiled program code |
US5913024A (en) * | 1996-02-09 | 1999-06-15 | Secure Computing Corporation | Secure server utilizing separate protocol stacks |
US7130888B1 (en) * | 1996-02-16 | 2006-10-31 | G&H Nevada-Tek | Method and apparatus for controlling a computer over a TCP/IP protocol network |
FR2745967B1 (en) * | 1996-03-07 | 1998-04-17 | Bull Cp8 | METHOD FOR SECURING ACCESS FROM A STATION TO AT LEAST ONE SERVER AND DEVICE IMPLEMENTING THE METHOD |
US5983090A (en) * | 1996-04-02 | 1999-11-09 | Kabushiki Kaisha Toshiba | Mobile communication system with access function to computer network |
US6003084A (en) * | 1996-09-13 | 1999-12-14 | Secure Computing Corporation | Secure network proxy for connecting entities |
US5983350A (en) * | 1996-09-18 | 1999-11-09 | Secure Computing Corporation | Secure firewall supporting different levels of authentication based on address or encryption status |
GB2317792B (en) * | 1996-09-18 | 2001-03-28 | Secure Computing Corp | Virtual private network on application gateway |
US6072942A (en) * | 1996-09-18 | 2000-06-06 | Secure Computing Corporation | System and method of electronic mail filtering using interconnected nodes |
US5950195A (en) * | 1996-09-18 | 1999-09-07 | Secure Computing Corporation | Generalized security policy management system and method |
US6130889A (en) * | 1996-10-02 | 2000-10-10 | International Business Machines Corporation | Determining and maintaining hop-count for switched networks |
US6005943A (en) * | 1996-10-29 | 1999-12-21 | Lucent Technologies Inc. | Electronic identifiers for network terminal devices |
GB9622535D0 (en) * | 1996-10-30 | 1997-01-08 | 3Com Ireland | Search apparatus |
US5915087A (en) * | 1996-12-12 | 1999-06-22 | Secure Computing Corporation | Transparent security proxy for unreliable message exchange protocols |
EP0951767A2 (en) | 1997-01-03 | 1999-10-27 | Fortress Technologies, Inc. | Improved network security device |
US5968133A (en) * | 1997-01-10 | 1999-10-19 | Secure Computing Corporation | Enhanced security network time synchronization device and method |
IL131553A0 (en) * | 1997-03-06 | 2001-01-28 | Software And Systems Engineeri | System and method for gaining access to information in a distributed computer system |
US6263444B1 (en) * | 1997-03-11 | 2001-07-17 | National Aerospace Laboratory Of Science & Technology Agency | Network unauthorized access analysis method, network unauthorized access analysis apparatus utilizing the method, and computer-readable recording medium having network unauthorized access analysis program recorded thereon |
ES2290986T3 (en) * | 1997-03-12 | 2008-02-16 | Nomadix, Inc. | NAME TRANSMITTER OR ROUTER. |
US6477648B1 (en) * | 1997-03-23 | 2002-11-05 | Novell, Inc. | Trusted workstation in a networked client/server computing system |
US7136359B1 (en) * | 1997-07-31 | 2006-11-14 | Cisco Technology, Inc. | Method and apparatus for transparently proxying a connection |
US6473406B1 (en) * | 1997-07-31 | 2002-10-29 | Cisco Technology, Inc. | Method and apparatus for transparently proxying a connection |
US6307837B1 (en) * | 1997-08-12 | 2001-10-23 | Nippon Telegraph And Telephone Corporation | Method and base station for packet transfer |
US6591291B1 (en) * | 1997-08-28 | 2003-07-08 | Lucent Technologies Inc. | System and method for providing anonymous remailing and filtering of electronic mail |
JPH11112561A (en) * | 1997-09-30 | 1999-04-23 | Sony Corp | Communication method and communication equipment |
US6158008A (en) * | 1997-10-23 | 2000-12-05 | At&T Wireless Svcs. Inc. | Method and apparatus for updating address lists for a packet filter processor |
US6343289B1 (en) * | 1997-10-31 | 2002-01-29 | Nortel Networks Limited | Efficient search and organization of a forwarding database or the like |
KR100246608B1 (en) * | 1997-11-13 | 2000-03-15 | 이계철 | A vicarious certificating and charging method in web infoshop service system |
SE513828C2 (en) * | 1998-07-02 | 2000-11-13 | Effnet Group Ab | Firewall device and method for controlling network data packet traffic between internal and external networks |
US6357010B1 (en) | 1998-02-17 | 2002-03-12 | Secure Computing Corporation | System and method for controlling access to documents stored on an internal network |
US6006272A (en) * | 1998-02-23 | 1999-12-21 | Lucent Technologies Inc. | Method for network address translation |
US6321336B1 (en) | 1998-03-13 | 2001-11-20 | Secure Computing Corporation | System and method for redirecting network traffic to provide secure communication |
US6182226B1 (en) | 1998-03-18 | 2001-01-30 | Secure Computing Corporation | System and method for controlling interactions between networks |
US6453419B1 (en) | 1998-03-18 | 2002-09-17 | Secure Computing Corporation | System and method for implementing a security policy |
US6738814B1 (en) * | 1998-03-18 | 2004-05-18 | Cisco Technology, Inc. | Method for blocking denial of service and address spoofing attacks on a private network |
US6681327B1 (en) * | 1998-04-02 | 2004-01-20 | Intel Corporation | Method and system for managing secure client-server transactions |
US6154839A (en) * | 1998-04-23 | 2000-11-28 | Vpnet Technologies, Inc. | Translating packet addresses based upon a user identifier |
US6711127B1 (en) * | 1998-07-31 | 2004-03-23 | General Dynamics Government Systems Corporation | System for intrusion detection and vulnerability analysis in a telecommunications signaling network |
US6618398B1 (en) * | 1998-08-06 | 2003-09-09 | Nortel Networks Limited | Address resolution for internet protocol sub-networks in asymmetric wireless networks |
US6317837B1 (en) * | 1998-09-01 | 2001-11-13 | Applianceware, Llc | Internal network node with dedicated firewall |
US6233626B1 (en) * | 1998-10-06 | 2001-05-15 | Schneider Automation Inc. | System for a modular terminal input/output interface for communicating messaging application layer over encoded ethernet to transport layer |
US10511573B2 (en) | 1998-10-30 | 2019-12-17 | Virnetx, Inc. | Agile network protocol for secure communications using secure domain names |
FI106417B (en) | 1998-12-08 | 2001-01-31 | Nokia Mobile Phones Ltd | Procedure for optimizing data transfer |
US8266266B2 (en) | 1998-12-08 | 2012-09-11 | Nomadix, Inc. | Systems and methods for providing dynamic network authorization, authentication and accounting |
US8713641B1 (en) | 1998-12-08 | 2014-04-29 | Nomadix, Inc. | Systems and methods for authorizing, authenticating and accounting users having transparent computer access to a network using a gateway device |
US7194554B1 (en) | 1998-12-08 | 2007-03-20 | Nomadix, Inc. | Systems and methods for providing dynamic network authorization authentication and accounting |
US6954775B1 (en) | 1999-01-15 | 2005-10-11 | Cisco Technology, Inc. | Parallel intrusion detection sensors with load balancing for high speed networks |
US7062550B1 (en) * | 1999-01-20 | 2006-06-13 | Bindview Corporation | Software-implemented method for identifying nodes on a network |
US7107614B1 (en) | 1999-01-29 | 2006-09-12 | International Business Machines Corporation | System and method for network address translation integration with IP security |
US6738377B1 (en) | 1999-01-29 | 2004-05-18 | International Business Machines Corporation | System and method for dynamic micro placement of IP connection filters |
US6615357B1 (en) * | 1999-01-29 | 2003-09-02 | International Business Machines Corporation | System and method for network address translation integration with IP security |
US8060926B1 (en) | 1999-03-16 | 2011-11-15 | Novell, Inc. | Techniques for securely managing and accelerating data delivery |
US7904951B1 (en) | 1999-03-16 | 2011-03-08 | Novell, Inc. | Techniques for securely accelerating external domains locally |
US6081900A (en) * | 1999-03-16 | 2000-06-27 | Novell, Inc. | Secure intranet access |
DE19914326A1 (en) * | 1999-03-30 | 2000-10-05 | Delphi 2 Creative Tech Gmbh | Procedure for using fractal semantic networks for all types of databank applications to enable fuzzy classifications to be used and much more flexible query procedures to be used than conventional databank structures |
US6591306B1 (en) | 1999-04-01 | 2003-07-08 | Nec Corporation | IP network access for portable devices |
US6947394B1 (en) * | 1999-04-09 | 2005-09-20 | Telefonaktiebolaget Lm Ericsson (Publ) | Flexible radio link control protocol |
US6393484B1 (en) | 1999-04-12 | 2002-05-21 | International Business Machines Corp. | System and method for controlled access to shared-medium public and semi-public internet protocol (IP) networks |
DE19917592A1 (en) | 1999-04-19 | 2000-10-26 | Delphi 2 Creative Tech Gmbh | Semantic network consisting of several units, in which the semantic network contains both semantic units which possess relational contents and connection units |
US6754214B1 (en) * | 1999-07-19 | 2004-06-22 | Dunti, Llc | Communication network having packetized security codes and a system for detecting security breach locations within the network |
US7778259B1 (en) | 1999-05-14 | 2010-08-17 | Dunti Llc | Network packet transmission mechanism |
US6957346B1 (en) | 1999-06-15 | 2005-10-18 | Ssh Communications Security Ltd. | Method and arrangement for providing security through network address translations using tunneling and compensations |
US7177952B1 (en) * | 1999-10-01 | 2007-02-13 | Nortel Networks Limited | Method and system for switching between two network access technologies without interrupting active network applications |
US6442696B1 (en) | 1999-10-05 | 2002-08-27 | Authoriszor, Inc. | System and method for extensible positive client identification |
WO2001031885A2 (en) | 1999-10-22 | 2001-05-03 | Nomadix, Inc. | Gateway device having an xml interface and associated method |
US6684253B1 (en) | 1999-11-18 | 2004-01-27 | Wachovia Bank, N.A., As Administrative Agent | Secure segregation of data of two or more domains or trust realms transmitted through a common data channel |
US6771649B1 (en) * | 1999-12-06 | 2004-08-03 | At&T Corp. | Middle approach to asynchronous and backward-compatible detection and prevention of ARP cache poisoning |
GB2357166B (en) * | 1999-12-07 | 2001-10-31 | Marconi Comm Ltd | Memory access system |
DE19960372A1 (en) * | 1999-12-14 | 2001-06-21 | Definiens Ag | Process for processing data structures |
US7079495B1 (en) | 2000-01-04 | 2006-07-18 | Cisco Technology, Inc. | System and method for enabling multicast telecommunications |
US7006494B1 (en) * | 2000-01-04 | 2006-02-28 | Cisco Technology, Inc. | System and method for a virtual telephony intermediary |
US6804254B1 (en) | 2000-01-04 | 2004-10-12 | Cisco Technology, Inc. | System and method for maintaining a communication link |
US7069432B1 (en) * | 2000-01-04 | 2006-06-27 | Cisco Technology, Inc. | System and method for providing security in a telecommunication network |
US7324948B2 (en) * | 2000-01-14 | 2008-01-29 | Carl Teo Balbach | Context-specific contact information |
KR100348612B1 (en) * | 2000-02-01 | 2002-08-13 | 엘지전자 주식회사 | Digital contents protection user encrypted key creation method |
US7814309B1 (en) * | 2000-02-29 | 2010-10-12 | Cisco Technology, Inc. | Method for checkpointing and reconstructing separated but interrelated data |
US6865673B1 (en) * | 2000-03-21 | 2005-03-08 | 3Com Corporation | Method for secure installation of device in packet based communication network |
AU2001257306A1 (en) * | 2000-04-27 | 2001-11-07 | Fortress Technologies, Inc. | A method and apparatus for integrating tunneling protocols with standard routingprotocols |
US7480939B1 (en) * | 2000-04-28 | 2009-01-20 | 3Com Corporation | Enhancement to authentication protocol that uses a key lease |
US6895502B1 (en) | 2000-06-08 | 2005-05-17 | Curriculum Corporation | Method and system for securely displaying and confirming request to perform operation on host computer |
US7757272B1 (en) * | 2000-06-14 | 2010-07-13 | Verizon Corporate Services Group, Inc. | Method and apparatus for dynamic mapping |
US8037530B1 (en) | 2000-08-28 | 2011-10-11 | Verizon Corporate Services Group Inc. | Method and apparatus for providing adaptive self-synchronized dynamic address translation as an intrusion detection sensor |
US7043633B1 (en) * | 2000-08-28 | 2006-05-09 | Verizon Corporation Services Group Inc. | Method and apparatus for providing adaptive self-synchronized dynamic address translation |
US6870841B1 (en) * | 2000-09-18 | 2005-03-22 | At&T Corp. | Controlled transmission across packet network |
US20020083344A1 (en) * | 2000-12-21 | 2002-06-27 | Vairavan Kannan P. | Integrated intelligent inter/intra networking device |
US20030084020A1 (en) * | 2000-12-22 | 2003-05-01 | Li Shu | Distributed fault tolerant and secure storage |
US6877042B2 (en) * | 2001-01-02 | 2005-04-05 | Dell Products L.P. | System and method for generating world wide names |
US7076538B2 (en) * | 2001-01-12 | 2006-07-11 | Lenovo (Singapore) Pte. Ltd. | Method and system for disguising a computer system's identity on a network |
US20020116644A1 (en) * | 2001-01-30 | 2002-08-22 | Galea Secured Networks Inc. | Adapter card for wirespeed security treatment of communications traffic |
EP1368726A4 (en) * | 2001-02-06 | 2005-04-06 | En Garde Systems | Apparatus and method for providing secure network communication |
US7739497B1 (en) * | 2001-03-21 | 2010-06-15 | Verizon Corporate Services Group Inc. | Method and apparatus for anonymous IP datagram exchange using dynamic network address translation |
US7174368B2 (en) * | 2001-03-27 | 2007-02-06 | Xante Corporation | Encrypted e-mail reader and responder system, method, and computer program product |
US7007169B2 (en) * | 2001-04-04 | 2006-02-28 | International Business Machines Corporation | Method and apparatus for protecting a web server against vandals attacks without restricting legitimate access |
US6920556B2 (en) * | 2001-07-20 | 2005-07-19 | International Business Machines Corporation | Methods, systems and computer program products for multi-packet message authentication for secured SSL-based communication sessions |
US7134012B2 (en) * | 2001-08-15 | 2006-11-07 | International Business Machines Corporation | Methods, systems and computer program products for detecting a spoofed source address in IP datagrams |
US7020784B2 (en) * | 2001-08-20 | 2006-03-28 | Yitran Communications Ltd. | Mechanism for detecting intrusion and jamming attempts in a shared media based communications network |
US20030046583A1 (en) * | 2001-08-30 | 2003-03-06 | Honeywell International Inc. | Automated configuration of security software suites |
US20030065941A1 (en) * | 2001-09-05 | 2003-04-03 | Ballard Clinton L. | Message handling with format translation and key management |
US7032244B2 (en) * | 2001-10-02 | 2006-04-18 | International Business Machines Corporation | Identifying potential intruders on a server |
US7171493B2 (en) * | 2001-12-19 | 2007-01-30 | The Charles Stark Draper Laboratory | Camouflage of network traffic to resist attack |
US7096490B2 (en) * | 2002-03-20 | 2006-08-22 | Actiontec Electronics, Inc. | Information routing device having an auto-configuration feature |
US7712130B2 (en) * | 2002-03-22 | 2010-05-04 | Masking Networks, Inc. | Multiconfigurable device masking shunt and method of use |
US7941559B2 (en) * | 2002-04-23 | 2011-05-10 | Tellabs Bedford, Inc. | Media access control address translation for a fiber to the home system |
US7191331B2 (en) * | 2002-06-13 | 2007-03-13 | Nvidia Corporation | Detection of support for security protocol and address translation integration |
US7346057B2 (en) * | 2002-07-31 | 2008-03-18 | Cisco Technology, Inc. | Method and apparatus for inter-layer binding inspection to prevent spoofing |
US7143435B1 (en) * | 2002-07-31 | 2006-11-28 | Cisco Technology, Inc. | Method and apparatus for registering auto-configured network addresses based on connection authentication |
AU2012202410B2 (en) * | 2002-07-31 | 2014-09-18 | Cisco Technology, Inc. | Method and apparatus for inspecting inter-layer address binding protocols |
US20040064725A1 (en) * | 2002-09-18 | 2004-04-01 | Microsoft Corporation | Method and system for detecting a communication problem in a computer network |
US8819285B1 (en) * | 2002-10-01 | 2014-08-26 | Trustwave Holdings, Inc. | System and method for managing network communications |
US7506360B1 (en) * | 2002-10-01 | 2009-03-17 | Mirage Networks, Inc. | Tracking communication for determining device states |
US7469418B1 (en) | 2002-10-01 | 2008-12-23 | Mirage Networks, Inc. | Deterring network incursion |
US7801361B2 (en) * | 2002-10-15 | 2010-09-21 | Definiens Ag | Analyzing pixel data using image, thematic and object layers of a computer-implemented network structure |
CN1326347C (en) * | 2002-12-30 | 2007-07-11 | 成都三零盛安信息系统有限公司 | Technological method for realizing multiple grade safety access control in network environment |
US8239942B2 (en) | 2002-12-30 | 2012-08-07 | Cisco Technology, Inc. | Parallel intrusion detection sensors with load balancing for high speed networks |
US7570648B2 (en) * | 2003-02-03 | 2009-08-04 | At&T Intellectual Property I, L.P. | Enhanced H-VPLS service architecture using control word |
DE10305413B4 (en) * | 2003-02-06 | 2006-04-20 | Innominate Security Technologies Ag | Method and arrangement for the transparent switching of data traffic between data processing devices and a corresponding computer program and a corresponding computer-readable storage medium |
KR100512954B1 (en) * | 2003-03-12 | 2005-09-07 | 삼성전자주식회사 | RR method for secure communication |
US20040184407A1 (en) * | 2003-03-21 | 2004-09-23 | Sbc Knowledge Ventures, L.P. | Operations, administration, and maintenance data packet and related testing methods |
US7643424B2 (en) | 2003-03-22 | 2010-01-05 | At&T Intellectual Property L, L.P. | Ethernet architecture with data packet encapsulation |
NZ543148A (en) * | 2003-03-24 | 2006-12-22 | Re Src Ltd | Multiconfigurable device masking shunt and method of use |
US7516487B1 (en) | 2003-05-21 | 2009-04-07 | Foundry Networks, Inc. | System and method for source IP anti-spoofing security |
US7523485B1 (en) | 2003-05-21 | 2009-04-21 | Foundry Networks, Inc. | System and method for source IP anti-spoofing security |
US20040255154A1 (en) * | 2003-06-11 | 2004-12-16 | Foundry Networks, Inc. | Multiple tiered network security system, method and apparatus |
US20050022017A1 (en) | 2003-06-24 | 2005-01-27 | Maufer Thomas A. | Data structures and state tracking for network protocol processing |
DE60315143T2 (en) * | 2003-06-25 | 2008-04-30 | Alcatel Lucent | Method and device for Ethernet MAC address translation in Ethernet access networks |
US7876772B2 (en) * | 2003-08-01 | 2011-01-25 | Foundry Networks, Llc | System, method and apparatus for providing multiple access modes in a data communications network |
JPWO2005015419A1 (en) * | 2003-08-12 | 2006-10-05 | ソニー株式会社 | COMMUNICATION PROCESSING DEVICE, COMMUNICATION CONTROL METHOD, AND COMPUTER PROGRAM |
JP4174392B2 (en) * | 2003-08-28 | 2008-10-29 | 日本電気株式会社 | Network unauthorized connection prevention system and network unauthorized connection prevention device |
US7735114B2 (en) * | 2003-09-04 | 2010-06-08 | Foundry Networks, Inc. | Multiple tiered network security system, method and apparatus using dynamic user policy assignment |
US7626948B1 (en) | 2003-09-12 | 2009-12-01 | Cisco Technology, Inc. | System and method for verifying the validity of a path in a network environment |
US7774833B1 (en) | 2003-09-23 | 2010-08-10 | Foundry Networks, Inc. | System and method for protecting CPU against remote access attacks |
US7643484B2 (en) * | 2003-09-26 | 2010-01-05 | Surgient, Inc. | Network abstraction and isolation layer rules-based federation and masquerading |
US7769004B2 (en) * | 2003-09-26 | 2010-08-03 | Surgient, Inc. | Network abstraction and isolation layer for masquerading machine identity of a computer |
US8528071B1 (en) | 2003-12-05 | 2013-09-03 | Foundry Networks, Llc | System and method for flexible authentication in a data communications network |
US8065720B1 (en) | 2004-01-06 | 2011-11-22 | Novell, Inc. | Techniques for managing secure communications |
US7298707B2 (en) * | 2004-01-21 | 2007-11-20 | Cisco Technology, Inc. | System and method for controlling the flooding of information in a network environment |
US7877595B2 (en) * | 2004-03-23 | 2011-01-25 | Harris Corporation | Modular cryptographic device and related methods |
US20050213762A1 (en) * | 2004-03-23 | 2005-09-29 | Harris Corporation | Modular cryptographic device and coupling therefor and related methods |
US7711963B2 (en) * | 2004-03-23 | 2010-05-04 | Harris Corporation | Modular cryptographic device providing enhanced interface protocol features and related methods |
US9003199B2 (en) * | 2004-03-23 | 2015-04-07 | Harris Corporation | Modular cryptographic device providing multi-mode wireless LAN operation features and related methods |
US7657755B2 (en) * | 2004-03-23 | 2010-02-02 | Harris Corporation | Modular cryptographic device providing status determining features and related methods |
US7644289B2 (en) * | 2004-03-23 | 2010-01-05 | Harris Corporation | Modular cryptographic device providing enhanced communication control features and related methods |
US20050235363A1 (en) * | 2004-04-06 | 2005-10-20 | Fortress Technologies, Inc. | Network, device, and/or user authentication in a secure communication network |
CN100463429C (en) * | 2004-04-19 | 2009-02-18 | 西安交通大学 | Method for preventing IP address from forged based on rewritten address |
US8554889B2 (en) * | 2004-04-21 | 2013-10-08 | Microsoft Corporation | Method, system and apparatus for managing computer identity |
US7971053B2 (en) * | 2004-05-26 | 2011-06-28 | At&T Intellectual Property I, L. P. | Methods, systems, and products for intrusion detection |
US8458453B1 (en) | 2004-06-11 | 2013-06-04 | Dunti Llc | Method and apparatus for securing communication over public network |
US7457244B1 (en) | 2004-06-24 | 2008-11-25 | Cisco Technology, Inc. | System and method for generating a traffic matrix in a network environment |
US7391730B1 (en) | 2004-07-21 | 2008-06-24 | Cisco Technology | System and method for synchronizing link state databases in a network environment |
US8234686B2 (en) * | 2004-08-25 | 2012-07-31 | Harris Corporation | System and method for creating a security application for programmable cryptography module |
WO2006039771A1 (en) * | 2004-10-12 | 2006-04-20 | Bce Inc. | System and method for access control |
US7760720B2 (en) * | 2004-11-09 | 2010-07-20 | Cisco Technology, Inc. | Translating native medium access control (MAC) addresses to hierarchical MAC addresses and their use |
US7742581B2 (en) | 2004-11-24 | 2010-06-22 | Value-Added Communications, Inc. | Electronic messaging exchange |
US9876915B2 (en) | 2005-01-28 | 2018-01-23 | Value-Added Communications, Inc. | Message exchange |
US9282188B2 (en) | 2005-01-28 | 2016-03-08 | Value-Added Communications, Inc. | Voice message exchange |
US7996894B1 (en) | 2005-02-15 | 2011-08-09 | Sonicwall, Inc. | MAC address modification of otherwise locally bridged client devices to provide security |
US20060250966A1 (en) * | 2005-05-03 | 2006-11-09 | Yuan-Chi Su | Method for local area network security |
US20060280138A1 (en) * | 2005-06-13 | 2006-12-14 | Nvidia Corporation | Wireless access point repeater |
US20070201490A1 (en) * | 2005-07-13 | 2007-08-30 | Mahamuni Atul B | System and method for implementing ethernet MAC address translation |
KR100736047B1 (en) * | 2005-07-28 | 2007-07-06 | 삼성전자주식회사 | Wireless networking device and authenticating method using the same |
US7966654B2 (en) | 2005-11-22 | 2011-06-21 | Fortinet, Inc. | Computerized system and method for policy-based content filtering |
US8468589B2 (en) | 2006-01-13 | 2013-06-18 | Fortinet, Inc. | Computerized system and method for advanced network content processing |
US7831996B2 (en) * | 2005-12-28 | 2010-11-09 | Foundry Networks, Llc | Authentication techniques |
US7832009B2 (en) * | 2005-12-28 | 2010-11-09 | Foundry Networks, Llc | Techniques for preventing attacks on computer systems and networks |
US8510812B2 (en) | 2006-03-15 | 2013-08-13 | Fortinet, Inc. | Computerized system and method for deployment of management tunnels |
US8078728B1 (en) | 2006-03-31 | 2011-12-13 | Quest Software, Inc. | Capacity pooling for application reservation and delivery |
US9166883B2 (en) | 2006-04-05 | 2015-10-20 | Joseph Robert Marchese | Network device detection, identification, and management |
US8086873B2 (en) * | 2006-06-05 | 2011-12-27 | Lenovo (Singapore) Pte. Ltd. | Method for controlling file access on computer systems |
US7917747B2 (en) * | 2007-03-22 | 2011-03-29 | Igt | Multi-party encryption systems and methods |
US8194674B1 (en) | 2007-12-20 | 2012-06-05 | Quest Software, Inc. | System and method for aggregating communications and for translating between overlapping internal network addresses and unique external network addresses |
US8683572B1 (en) | 2008-01-24 | 2014-03-25 | Dunti Llc | Method and apparatus for providing continuous user verification in a packet-based network |
US8953601B2 (en) * | 2008-05-13 | 2015-02-10 | Futurewei Technologies, Inc. | Internet protocol version six (IPv6) addressing and packet filtering in broadband networks |
EP2134029A1 (en) * | 2008-06-09 | 2009-12-16 | THOMSON Licensing | Network device and method for obtaining terminal multicast status |
US9621714B2 (en) | 2009-01-27 | 2017-04-11 | Value-Added Communications, Inc. | System and method for electronic notification in institutional communication |
US8934625B2 (en) | 2009-03-25 | 2015-01-13 | Pacid Technologies, Llc | Method and system for securing communication |
US20110307707A1 (en) | 2009-03-25 | 2011-12-15 | Pacid Technologies, Llc | Method and system for securing a file |
TW201105083A (en) | 2009-03-25 | 2011-02-01 | Pacid Technologies Llc | Token for securing communication |
WO2010111448A1 (en) | 2009-03-25 | 2010-09-30 | Pacid Technologies, Llc | Method and system for securing communication |
US8726032B2 (en) | 2009-03-25 | 2014-05-13 | Pacid Technologies, Llc | System and method for protecting secrets file |
US9325802B2 (en) * | 2009-07-16 | 2016-04-26 | Microsoft Technology Licensing, Llc | Hierarchical scale unit values for storing instances of data among nodes of a distributed store |
US8640221B2 (en) * | 2009-12-11 | 2014-01-28 | Juniper Networks, Inc. | Media access control address translation in virtualized environments |
JP5727258B2 (en) * | 2011-02-25 | 2015-06-03 | ウイングアーク1st株式会社 | Distributed database system |
CN102739506B (en) * | 2011-04-13 | 2015-09-09 | 李小林 | VPN traffic is carried out to the method for transparent transmission |
US8479021B2 (en) | 2011-09-29 | 2013-07-02 | Pacid Technologies, Llc | Secure island computing system and method |
US8605895B2 (en) * | 2011-12-13 | 2013-12-10 | International Business Machines Corporation | Computing the eth root of a number using a variant of the RSA algorithm (for even e's) |
US8819818B2 (en) * | 2012-02-09 | 2014-08-26 | Harris Corporation | Dynamic computer network with variable identity parameters |
US8826388B2 (en) | 2012-02-16 | 2014-09-02 | Sonicwall, Inc. | Mobile device identify factor for access control policies |
US10091201B2 (en) | 2012-02-16 | 2018-10-02 | Sonicwall Inc. | Mobile device identify factor for access control policies |
US9130907B2 (en) | 2012-05-01 | 2015-09-08 | Harris Corporation | Switch for communicating data in a dynamic computer network |
US9154458B2 (en) | 2012-05-01 | 2015-10-06 | Harris Corporation | Systems and methods for implementing moving target technology in legacy hardware |
CN103944865B (en) * | 2013-01-22 | 2018-11-27 | 横河电机株式会社 | Insulation blocking system and its method for executing bi-directional data packet filtering inspection |
US9172721B2 (en) | 2013-07-16 | 2015-10-27 | Fortinet, Inc. | Scalable inline behavioral DDOS attack mitigation |
EP3022652A2 (en) | 2013-07-19 | 2016-05-25 | eyeQ Insights | System for monitoring and analyzing behavior and uses thereof |
US9503324B2 (en) | 2013-11-05 | 2016-11-22 | Harris Corporation | Systems and methods for enterprise mission management of a computer network |
US9264496B2 (en) | 2013-11-18 | 2016-02-16 | Harris Corporation | Session hopping |
US9338183B2 (en) | 2013-11-18 | 2016-05-10 | Harris Corporation | Session hopping |
US10122708B2 (en) | 2013-11-21 | 2018-11-06 | Harris Corporation | Systems and methods for deployment of mission plans using access control technologies |
CN104581715B (en) * | 2014-11-22 | 2018-06-26 | 杭州木梢科技有限公司 | The sensor-based system cryptographic key protection method and radio reception device of Internet of Things field |
CN106083589B (en) * | 2016-06-14 | 2019-03-22 | 常州大学 | A kind of nitrogen-containing ordered mesopore carbon material catalyst synthesizes the application in advanced 'beta '-ketoester in transesterification |
CN106357690B (en) * | 2016-11-08 | 2019-12-10 | 浙江中控技术股份有限公司 | data transmission method, data sending device and data receiving device |
US20180234535A1 (en) * | 2017-02-10 | 2018-08-16 | Mediatek Inc. | Method and apparatus for communication |
US10749827B2 (en) | 2017-05-11 | 2020-08-18 | Global Tel*Link Corporation | System and method for inmate notification and training in a controlled environment facility |
CN108471408A (en) * | 2018-03-13 | 2018-08-31 | 广州市冰海网络技术有限公司 | A kind of network security encryption device |
CN109194676B (en) * | 2018-09-21 | 2020-11-27 | 无锡润盟软件有限公司 | Data stream encryption method and data stream decryption method |
Family Cites Families (80)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4182933A (en) * | 1969-02-14 | 1980-01-08 | The United States Of America As Represented By The Secretary Of The Army | Secure communication system with remote key setting |
US3816666A (en) * | 1972-10-02 | 1974-06-11 | Communications Satellite Corp | System for changing the burst format in a tdma communication system |
US4185166A (en) * | 1975-04-14 | 1980-01-22 | Datotek, Inc. | Multi-mode digital enciphering system |
US4160120A (en) * | 1977-11-17 | 1979-07-03 | Burroughs Corporation | Link encryption device |
US4159468A (en) * | 1977-11-17 | 1979-06-26 | Burroughs Corporation | Communications line authentication device |
US4238854A (en) * | 1977-12-05 | 1980-12-09 | International Business Machines Corporation | Cryptographic file security for single domain networks |
US4203166A (en) * | 1977-12-05 | 1980-05-13 | International Business Machines Corporation | Cryptographic file security for multiple domain networks |
US4227253A (en) * | 1977-12-05 | 1980-10-07 | International Business Machines Corporation | Cryptographic communication security for multiple domain networks |
US4249180A (en) * | 1978-09-20 | 1981-02-03 | Northern Telecom Limited | Past dependent microcomputer cipher apparatus |
GB2140656A (en) * | 1983-05-13 | 1984-11-28 | Philips Electronic Associated | Television transmission system |
US4633391A (en) * | 1983-10-21 | 1986-12-30 | Storage Technology Partners Ii | Extended index for digital information storage and retrieval device |
US4621321A (en) * | 1984-02-16 | 1986-11-04 | Honeywell Inc. | Secure data processing system architecture |
US4829569A (en) * | 1984-09-21 | 1989-05-09 | Scientific-Atlanta, Inc. | Communication of individual messages to subscribers in a subscription television system |
US4757536A (en) * | 1984-10-17 | 1988-07-12 | General Electric Company | Method and apparatus for transceiving cryptographically encoded digital data |
US4799153A (en) * | 1984-12-14 | 1989-01-17 | Telenet Communications Corporation | Method and apparatus for enhancing security of communications in a packet-switched data communications system |
US4713753A (en) * | 1985-02-21 | 1987-12-15 | Honeywell Inc. | Secure data processing system architecture with format control |
US4802220A (en) * | 1985-03-20 | 1989-01-31 | American Telephone And Telegraph Company, At&T Bell Laboratories | Method and apparatus for multi-channel communication security |
US4901348A (en) * | 1985-12-24 | 1990-02-13 | American Telephone And Telegraph Company | Data transmission security arrangement for a plurality of data stations sharing access to a communication network |
US4837822A (en) * | 1986-04-08 | 1989-06-06 | Schlage Lock Company | Cryptographic based electronic lock system and method of operation |
US4731841A (en) * | 1986-06-16 | 1988-03-15 | Applied Information Technologies Research Center | Field initialized authentication system for protective security of electronic information networks |
US4829560A (en) * | 1987-01-30 | 1989-05-09 | Spectradyne | Communications system for use in a hotel/motel |
GB8704883D0 (en) * | 1987-03-03 | 1987-04-08 | Hewlett Packard Co | Secure information storage |
EP0287720B1 (en) * | 1987-04-22 | 1992-01-08 | International Business Machines Corporation | Management of cryptographic keys |
US4956803A (en) * | 1987-07-02 | 1990-09-11 | International Business Machines Corporation | Sequentially processing data in a cached data storage system |
US4916704A (en) * | 1987-09-04 | 1990-04-10 | Digital Equipment Corporation | Interface of non-fault tolerant components to fault tolerant system |
US4924513A (en) * | 1987-09-25 | 1990-05-08 | Digital Equipment Corporation | Apparatus and method for secure transmission of data over an unsecure transmission channel |
JPH0732373B2 (en) * | 1988-03-26 | 1995-04-10 | 株式会社ケンウッド | One-way address transmission method for PCM music broadcasting |
US4980913A (en) * | 1988-04-19 | 1990-12-25 | Vindicator Corporation | Security system network |
US5001755A (en) * | 1988-04-19 | 1991-03-19 | Vindicator Corporation | Security system network |
US4910777A (en) * | 1988-09-20 | 1990-03-20 | At&T Bell Laboratories | Packet switching architecture providing encryption across packets |
US4965804A (en) * | 1989-02-03 | 1990-10-23 | Racal Data Communications Inc. | Key management for encrypted packet based networks |
US4933971A (en) * | 1989-03-14 | 1990-06-12 | Tandem Computers Incorporated | Method for encrypting transmitted data using a unique key |
US4956863A (en) * | 1989-04-17 | 1990-09-11 | Trw Inc. | Cryptographic method and apparatus for public key exchange with authentication |
GB8927623D0 (en) * | 1989-12-06 | 1990-02-07 | Bicc Plc | Repeaters for secure local area networks |
US5056140A (en) * | 1990-02-22 | 1991-10-08 | Blanton Kimbell | Communication security accessing system and process |
US5204961A (en) * | 1990-06-25 | 1993-04-20 | Digital Equipment Corporation | Computer network operating with multilevel hierarchical security with selectable common trust realms and corresponding security protocols |
US5086469A (en) * | 1990-06-29 | 1992-02-04 | Digital Equipment Corporation | Encryption with selective disclosure of protocol identifiers |
US5309437A (en) * | 1990-06-29 | 1994-05-03 | Digital Equipment Corporation | Bridge-like internet protocol router |
US5161193A (en) * | 1990-06-29 | 1992-11-03 | Digital Equipment Corporation | Pipelined cryptography processor and method for its use in communication networks |
US5070528A (en) * | 1990-06-29 | 1991-12-03 | Digital Equipment Corporation | Generic encryption technique for communication networks |
GB9015799D0 (en) * | 1990-07-18 | 1991-06-12 | Plessey Telecomm | A data communication system |
US5245696A (en) * | 1990-11-21 | 1993-09-14 | Ricoh Co. Ltd. | Evolution and learning in neural networks: the number and distribution of learning trials affect the rate of evolution |
US5182554A (en) * | 1990-12-18 | 1993-01-26 | International Business Machines Corporation | Third party evavesdropping for bus control |
US5272754A (en) * | 1991-03-28 | 1993-12-21 | Secure Computing Corporation | Secure computer interface |
US5222137A (en) * | 1991-04-03 | 1993-06-22 | Motorola, Inc. | Dynamic encryption key selection for encrypted radio transmissions |
US5179554A (en) * | 1991-04-08 | 1993-01-12 | Digital Equipment Corporation | Automatic association of local area network station addresses with a repeater port |
JP2862030B2 (en) * | 1991-06-13 | 1999-02-24 | 三菱電機株式会社 | Encryption method |
US5577209A (en) * | 1991-07-11 | 1996-11-19 | Itt Corporation | Apparatus and method for providing multi-level security for communication among computers and terminals on a network |
US5177788A (en) * | 1991-10-15 | 1993-01-05 | Ungermann-Bass, Inc. | Network message security method and apparatus |
US5222140A (en) * | 1991-11-08 | 1993-06-22 | Bell Communications Research, Inc. | Cryptographic method for key agreement and user authentication |
FR2686755A1 (en) * | 1992-01-28 | 1993-07-30 | Electricite De France | METHOD FOR ENCRYPTING MESSAGES TRANSMITTED BETWEEN INTERCONNECTED NETWORKS, ENCRYPTION APPARATUS AND DEVICE FOR COMMUNICATING ENCRYPTED DATA USING SUCH A METHOD. |
US5537099A (en) * | 1992-04-16 | 1996-07-16 | Bay Networks, Inc. | Receiving port security in a network concentrator |
US5276735A (en) * | 1992-04-17 | 1994-01-04 | Secure Computing Corporation | Data enclave and trusted path system |
US5311593A (en) * | 1992-05-13 | 1994-05-10 | Chipcom Corporation | Security system for a network concentrator |
IL102394A (en) * | 1992-07-02 | 1996-08-04 | Lannet Data Communications Ltd | Method and apparatus for secure data transmission |
US5596718A (en) * | 1992-07-10 | 1997-01-21 | Secure Computing Corporation | Secure computer network using trusted path subsystem which encrypts/decrypts and communicates with user through local workstation user I/O devices without utilizing workstation processor |
US5268962A (en) * | 1992-07-21 | 1993-12-07 | Digital Equipment Corporation | Computer network with modified host-to-host encryption keys |
US5361359A (en) * | 1992-08-31 | 1994-11-01 | Trusted Information Systems, Inc. | System and method for controlling the use of a computer |
IL103467A (en) * | 1992-10-18 | 1996-03-31 | Lannet Data Communications Ltd | Network with a security capability |
US5414694A (en) * | 1993-02-19 | 1995-05-09 | Advanced Micro Devices, Inc. | Address tracking over repeater based networks |
US5299263A (en) * | 1993-03-04 | 1994-03-29 | Bell Communications Research, Inc. | Two-way public key authentication and key agreement for low-cost terminals |
US5442708A (en) * | 1993-03-09 | 1995-08-15 | Uunet Technologies, Inc. | Computer network encryption/decryption device |
US5444782A (en) * | 1993-03-09 | 1995-08-22 | Uunet Technologies, Inc. | Computer network encryption/decryption device |
US5353283A (en) * | 1993-05-28 | 1994-10-04 | Bell Communications Research, Inc. | General internet method for routing packets in a communications network |
US5394402A (en) * | 1993-06-17 | 1995-02-28 | Ascom Timeplex Trading Ag | Hub for segmented virtual local area network with shared media access |
US5331637A (en) * | 1993-07-30 | 1994-07-19 | Bell Communications Research, Inc. | Multicast routing using core based trees |
JP3263878B2 (en) * | 1993-10-06 | 2002-03-11 | 日本電信電話株式会社 | Cryptographic communication system |
US5386471A (en) * | 1994-01-25 | 1995-01-31 | Hughes Aircraft Company | Method and apparatus for securely conveying network control data across a cryptographic boundary |
US5394469A (en) * | 1994-02-18 | 1995-02-28 | Infosafe Systems, Inc. | Method and apparatus for retrieving secure information from mass storage media |
US5416842A (en) * | 1994-06-10 | 1995-05-16 | Sun Microsystems, Inc. | Method and apparatus for key-management scheme for use with internet protocols at site firewalls |
US5588060A (en) * | 1994-06-10 | 1996-12-24 | Sun Microsystems, Inc. | Method and apparatus for a key-management scheme for internet protocols |
US5557765A (en) * | 1994-08-11 | 1996-09-17 | Trusted Information Systems, Inc. | System and method for data recovery |
US5557346A (en) * | 1994-08-11 | 1996-09-17 | Trusted Information Systems, Inc. | System and method for key escrow encryption |
US5548646A (en) * | 1994-09-15 | 1996-08-20 | Sun Microsystems, Inc. | System for signatureless transmission and reception of data packets between computer networks |
US5590201A (en) * | 1994-11-10 | 1996-12-31 | Advanced Micro Devices Inc. | Programmable source address locking mechanism for secure networks |
US5623601A (en) * | 1994-11-18 | 1997-04-22 | Milkway Networks Corporation | Apparatus and method for providing a secure gateway for communication and data exchanges between networks |
US5550984A (en) * | 1994-12-07 | 1996-08-27 | Matsushita Electric Corporation Of America | Security system for preventing unauthorized communications between networks by translating communications received in ip protocol to non-ip protocol to remove address and routing services information |
US5548649A (en) * | 1995-03-28 | 1996-08-20 | Iowa State University Research Foundation | Network security bridge and associated method |
US5699513A (en) * | 1995-03-31 | 1997-12-16 | Motorola, Inc. | Method for secure network access via message intercept |
US5781550A (en) * | 1996-02-02 | 1998-07-14 | Digital Equipment Corporation | Transparent and secure network gateway |
-
1995
- 1995-09-18 US US08/529,497 patent/US5757924A/en not_active Expired - Fee Related
-
1996
- 1996-09-06 CN CN96191481A patent/CN1173256A/en active Pending
- 1996-09-06 WO PCT/US1996/014285 patent/WO1997013340A1/en not_active Application Discontinuation
- 1996-09-06 SG SG200001507A patent/SG96185A1/en unknown
- 1996-09-06 EP EP96932962A patent/EP0872074A1/en not_active Withdrawn
- 1996-09-06 CA CA002211301A patent/CA2211301C/en not_active Expired - Fee Related
- 1996-09-06 SG SG200001506A patent/SG92687A1/en unknown
- 1996-09-06 AU AU71548/96A patent/AU725712B2/en not_active Ceased
-
1997
- 1997-07-28 IL IL12141697A patent/IL121416A/en not_active IP Right Cessation
-
1998
- 1998-01-21 US US09/010,102 patent/US6151679A/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11122054B2 (en) | 2019-08-27 | 2021-09-14 | Bank Of America Corporation | Security tool |
US11949684B2 (en) | 2019-08-27 | 2024-04-02 | Bank Of America Corporation | Security tool |
Also Published As
Publication number | Publication date |
---|---|
US5757924A (en) | 1998-05-26 |
IL121416A0 (en) | 1999-10-28 |
AU725712B2 (en) | 2000-10-19 |
EP0872074A1 (en) | 1998-10-21 |
AU7154896A (en) | 1997-04-28 |
WO1997013340A1 (en) | 1997-04-10 |
SG96185A1 (en) | 2003-05-23 |
SG92687A1 (en) | 2002-11-19 |
CN1173256A (en) | 1998-02-11 |
IL121416A (en) | 2001-09-13 |
CA2211301A1 (en) | 1997-04-10 |
US6151679A (en) | 2000-11-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2211301C (en) | Network security device | |
AU743258B2 (en) | Improved network security device | |
US9838362B2 (en) | Method and system for sending a message through a secure connection | |
US5416842A (en) | Method and apparatus for key-management scheme for use with internet protocols at site firewalls | |
US7043633B1 (en) | Method and apparatus for providing adaptive self-synchronized dynamic address translation | |
US5588060A (en) | Method and apparatus for a key-management scheme for internet protocols | |
Oppliger | Internet security: firewalls and beyond | |
US6826684B1 (en) | Sliding scale adaptive self-synchronized dynamic address translation | |
EP0876027B1 (en) | Method and apparatus for achieving perfect forward secrecy in closed user groups | |
EP0693836A1 (en) | Method and apparatus for a key-management scheme for internet protocols. | |
Goldberg et al. | Freedom network 1.0 architecture and protocols | |
EP2043296A1 (en) | Relay device | |
US20040260921A1 (en) | Cryptographic method, system and engine for enciphered message transmission | |
CA2437548A1 (en) | Apparatus and method for providing secure network communication | |
WO1999049613A1 (en) | Cryptographic key-recovery mechanism | |
Kruegel et al. | Internet security | |
JP2006295401A (en) | Relaying apparatus | |
Oppliger | Firewalls | |
Li et al. | An enhanced IPSec for anonymous internet communication | |
Neiman | Hash stamp marking scheme for packet traceback | |
Yener | Internet Security | |
Gupta | Outline of the Tutorial | |
Kasthuribai et al. | A Secured Communication between Web Servers in a Network | |
KR20090032072A (en) | Relay device | |
AU2002322451A1 (en) | Apparatus and method for providing secure network communication |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKLA | Lapsed |