A method and device for creating ciphertext from plaintext, and for decoding ciphertext, utilizing a tree structure for both encoding and decoding, the tree having leaves which are associated with plaintext symbols and the branches having assigned thereto a member of the ciphertext alphabet so that when...http://www.google.com/patents/US7508935?utm_source=gb-gplus-sharePatent US7508935 - Cryptosystem for data security
