|Publication number||USRE42171 E1|
|Application number||US 12/252,300|
|Publication date||Feb 22, 2011|
|Filing date||Oct 15, 2008|
|Priority date||Mar 17, 1999|
|Also published as||CN1267856A, CN1783102A, US7130426, USRE41942, USRE42106, USRE42107|
|Publication number||12252300, 252300, US RE42171 E1, US RE42171E1, US-E1-RE42171, USRE42171 E1, USRE42171E1|
|Inventors||Ghun-Up Cha, Myeong-Joon Kang, Han Jung|
|Original Assignee||Lg Electronics Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (45), Non-Patent Citations (3), Referenced by (1), Classifications (44), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a reissue application of application Ser. No. 09/527,670 filed on Mar. 17, 2000 (now U.S. Pat. No. 7,130,246 ). The present application also claims priority to Korean Patent Application No. 1999/9014 filed in the Republic of Korea on Mar. 17, 1999, which is incorporated by reference it its entirety. There are multiple reissue applications related to U.S. Pat. No. 7,130,246 including Ser. No. 12/252,295 filed Oct. 15, 2008; Ser. No. 12/252,300 filed Oct. 15, 2008 (the present application); Ser. No. 12/252,306 filed Oct. 15, 2008; and Ser. No. 12/252,311 filed Oct. 15, 2008.
1. Field of the Invention
The present invention relates to digital data file encryption in which an encrypted digital data file is prevented from illicit interception and decoding when digital audio data or digital video data is transmitted to a personal computer through a computer communication network and, in turn, downloaded to a digital data player such as an MP3 player.
2. Description of the Related Art
MP3 (shorthand for MPEG-1 Layer 3 Audio) is one of various available digital data formats for audio data. An MP3 player is a new notional, portable digital device capable of readily downloading and reproducing desired data from a computer communication network using an audio data compression coding technique prescribed in MPEG-1 Layer 3. The MP3 player has few faults and excellent sound quality because it stores a file in the form of digital data. Further, the MP3 player is small in size and light in weight, thereby assuring high portability such that a user can carry it even during his physical exercise. For these reasons, this product is a viable alternative to a portable cassette tape recorder and compact disk (CD) player.
With reference to
The operation of the conventional arrangement with the above-mentioned construction will now be described.
In order to legally receive a desired digital data file from the digital data server 10, the user has to register with a digital data file supplier. During user registration, the user is assigned an ID number and password from the digital data file supplier. Then, the user downloads a digital data player 22 in software form from the digital data server 10 through a communication network and installs the downloaded digital data player 22 in the personal computer 20.
Thereafter, to download a desired digital data file from the digital data server 10 through the personal computer 20 and communication network, the user transmits his ID number and password to the digital data server 10 through the personal computer 20 and communication network. The digital data server 10 identifies the user on the basis of the transmitted ID number and password and supplies the desired digital data file to the user in accordance with the identification. At this time, the digital data server 10 encrypts the digital data file using the user's ID number as an encryption key and transmits the encrypted digital data file to the personal computer 20.
The personal computer 20 stores the digital data file transmitted from the digital data server 10 on the hard disk 21. Then, upon receiving a reproduction request from the user, the personal computer 20 decrypts and reproduces the stored digital data file via the digital data software player 22. As a result, the user is able to listen to desired music through the personal computer 20.
On the other hand, if the user intends to listen to music in a digital data file form using the portable digital data playing device 30, then the personal computer 20 decrypts the digital data file, stored on the hard disk 21 with the digital data software player 22, and sends the decrypted digital data file to the digital data playing device 30 through a download unit 23 therein and the communication network.
Then, the digital data playing device 30 stores the digital data file, sent along the above path, in the memory 42 of the memory unit 40, which is typically in the form of a removable card. If the user requests the digital data player 30 to reproduce the digital data file stored in the memory 42, then the digital data player 30 reads the stored digital data file from the memory 42 and reproduces it through a decoder 32 therein. As a result, the user can listen to desired music anywhere using the digital data player 30.
However, the above-mentioned conventional arrangement has a disadvantage in that the digital data file may be intercepted from the communication network during downloading from the personal computer to the digital data playing device (or from the digital data playing device to the memory card) in an unencrypted condition. Such an interception of the unencrypted digital data file makes it impossible to protect the copyright of a music copyright holder and music copyright associates (for example, a music producer and planner taking charge of music production, duplication and distribution). In order to solve the above problem, a conventional powerful encryption method may be used to powerfully encrypt the digital data file and send it to the digital data player. However, such powerful encryption, in turn, requires a powerful decryption function, thereby increasing the cost of the digital data player.
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an encryption system in which illegal outflow of a digital data file, such as MP3, downloaded from a server can be prevented, with no additional increase in cost.
In accordance with one aspect of the present invention, there is provided a method for encrypting digital data including decrypting digital data which has been encrypted at a high encryption level, storing a predetermined amount of the decrypted digital data in a buffer, reencrypting output digital data from the buffer at a low encryption level; and transferring the reencrypted digital data to a digital data player or a data storage medium.
In accordance with another aspect of the present invention, there is provided a method for encrypting digital data including determining whether digital data which has been encrypted at a high encryption level must be protected from unauthorized copying, decrypting the digital data, transferring the decrypted digital data to a digital data player or a data storage medium if the decrypted digital data need not be protected from unauthorized copying, and reencrypting the decrypted digital data at a low encryption level if the decrypted digital data must be protected from unauthorized copying.
In accordance with a further aspect of the present invention, there is provided a program (or script) embodied on a computer-readable medium for encrypting or decrypting a digital data file, the computer-readable-medium-embodied program including a first program code segment to receive and store digital data encrypted to a high level and an encryption key, a second program code segment to decrypt the stored digital data using the encryption key, a third program code segment to store a predetermined amount of the decrypted digital data in a buffer, and a fourth program code segment to reencrypt the digital data from the buffer to a low level and download the reencrypted digital data to a digital data player or a data storage medium.
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
With reference to
First, the user must register with a digital data file supplier to legally receive a desired digital data file from a digital data server 110 (
Thereafter, the user transmits his ID number and password to the digital data server 110 through the personal computer 120 and communication network to download a desired digital data file from the digital data server 110 through the communication network. The digital data server 110 identifies the user on the basis of the transmitted ID number and password and supplies the desired digital data file to the user in accordance with the identification (
The personal computer 120 stores the digital data file transmitted from the digital data server 110 on a hard disk 121 therein (
On the other hand, in the case where the user intends to listen to music in a digital data file form using a digital data playing device 130, the personal computer 120 has to transmit the desired digital data file to the digital data playing device 130. In this case, if the digital data file is powerfully encrypted and downloaded to the digital data playing device 130, a corresponding powerful decryption function must be performed in the digital data playing device 130. Such powerful decryption would result in an increase in cost of the digital data playing device 130. Alternatively, when the digital data is downloaded under the decrypted, or non-processed, condition, it is subject to illicit diversion during transmission, and subsequent uncontrolled distribution. In order to overcome the above problems, the present encryption apparatus encrypts and downloads the digital data file in the following manner.
In the personal computer 120, an encrypted data file from the hard disk 121 is decrypted by an encryption decryptor 123, temporarily stored in a buffer 124, and then transferred to an encryption/download unit 125 (
Changing the size of the buffer 124 appropriately as needed causes the decrypted data not to be normally used even if it is hacked or illicitly diverted while being stored in the buffer 124. As a result, the hacking or illicit diversion of the data file so protected does not frustrate the purposes of copyright laws, because the diverted file cannot be used
For example, assume that a digital data file to be protected in copyright has a three-minute capacity and it is normally reproducible only when being stored in the buffer 124 in the unit of two-second amounts. In this case, the one-second amount-unit storage of the digital data file in the buffer 124 causes the digital data file not to be normally used even when it illegally flows. As a result, the copyright of the digital data file can be protected. There may be various methods for identifying files to be protected in copyright. One such method is to identify files to be protected in copyright on the basis of extension indexes.
In the case where the output digital data from the buffer 124 need not be protected in copyright, it is downloaded directly in unencrypted form to the digital data playing device 130 through the encryption/download unit 125 (
Alternatively, the file encrypted as shown in
The digital data playing device 130 stores the digital data file from the personal computer 120, encrypted and downloaded in the above manner, in a memory 142 of a data storage medium 140 which may be in the form of a removable card. If the user requests the digital data playing device 130 to reproduce the digital data file stored in the memory 142, then the digital data playing device 130 reads the stored digital data file from the memory 142 and reproduces it through a decoder 132 therein. At this time, the digital data file read from the data storage medium 140 has to be decrypted for the reproduction because it is in an encrypted form. For this reason, in the digital data playing device 130, a microcomputer 131 decrypts the digital data file read from the data storage medium 140 on the basis of the encryption key used in the above encryption procedure and outputs the decrypted digital data file to an output line through the decoder 132. Because of the weak encryption shown, for example, in
In accordance with the present invention, the above encryption method may be implemented by one program on a recording medium. The encryption program is configured to receive and store both digital data encrypted to a high level and an encryption key, decrypt the encrypted digital data according to the encryption key, store the decrypted digital data in a buffer in a predetermined unit of size, reencrypt output digital data from the buffer to a low level and download the reencrypted digital data to a digital data player or a data storage medium. This encryption program is stored on a single recording medium for use in the digital data encryption of the present invention.
Thereafter, acccording to the present invention as shown in
On the other hand, in the case where it is determined at the above Step 440 that the copyright of the downloaded file must be protected, the personal computer first checks the capacity of the downloaded file at Step 450 and then sets an effective capacity of a buffer in accordance with the checked result ate Step 460. Then, the personal computer decrypts the downloaded file according to the encryption key at Step 470 and stores the decrypted file in the buffer at Step 480 in such a manner that the decrypted file cannot be normally reproduced even when it is hacked in process of being downloaded to the digital data player. The digital data file stored in the buffer is encrypted to a low level at Step 490. This low level encryption does not require a separate microprocessor which is typically used for the high level encryption or powerful encryption, thereby avoiding an increase in cost of the associated playing device. Then, the digital data file encrypted to the low level is downloaded to the digital data playing device at Step 500.
With reference to
If the downloaded digital data file need not be protected in copyright, then it is decrypted and downloaded directly to a digital data player at Step 510. In this case, because no copyright problem is caused even when the downloaded file is hacked/diverted, there is no necessity for encrypting the downloaded file to send it to the digital data player. On the other hand, in the case where it is determined at the above step 440 that the copyright of the downloaded file must be protected, the digital data file stored in the buffer is encrypted to a low level at step 490. As described above with reference to
According to the present invention, a digital data file downloaded from a single server is decrypted, stored in the buffer in a predetermined unit of size, encrypted in a somewhat simple manner and downloaded to the digital data player. Digital data files downloaded from a plurality of servers are decrypted in individual decryption manners, encrypted in the simple manner as mentioned above and downloaded to the digital data player. Therefore, it is possible to reliably protect the copyright of a given digital data file without increasing the cost of the digital data player due to the decryption function.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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|U.S. Classification||726/26, 726/27, 705/50, 705/51, 380/200, 380/201, 380/237, 713/189, 713/193|
|International Classification||H04L9/00, G06F21/00, G06F12/16, H04L29/06, G06F21/24, G10L11/00, G06F12/14, G10K15/02, G09C1/00, G06F7/00, G06F9/06|
|Cooperative Classification||G11B20/0021, G11B20/00224, G11B2020/10759, G11B20/00478, H04L63/0478, G11B20/00086, H04L63/0464, G11B20/00144, G11B20/00869, G11B20/00152, H04L9/14, G11B2020/1062, H04L2209/605, H04L9/088|
|European Classification||H04L9/14, G11B20/00P, H04L63/04B12, G11B20/00P12B, G11B20/00P2B, G11B20/00P5A2, G11B20/00P5, H04L63/04B8, G11B20/00P5E, G11B20/00P2A|