Encryption and decryption of information of a message is performed by partitioning a plaintext message into blocks of binary digits and by further partitioning said blocks into subblocks which are interpreted as elements in a Galois-field. A plaintext matrix (M) of said elements is multiplied by a first...http://www.google.ca/patents/US4322577?utm_source=gb-gplus-sharePatent US4322577 - Cryptosystem
