PROCESS OF FORMATION OF ENCRYPTION/DECRYPTION KEY Russian patent published in 2002 - IPC

FIELD: cryptography. SUBSTANCE: invention can be used as individual element in development of symmetrical cryptographic systems designed to transmit encoded speech, sound, television and other messages. Technical result achieved by realization of proposed technical decision lies in development of method of formation of encryption/decryption key with provision for increased stability of formed encryption/decryption key and for compromising transgressor. Process of formation of encryption/decryption key ensures formation of initial sequence at receiving side of communication route, its encryption, extraction of block of test symbols from encrypted initial sequence, its transmission over backward communication channel without any errors to transmitting side of route, formation of decrypted sequence at transmitting side of route, formation of hashing function of sequences at transmitting side of route, its transmission without any errors over forward communication channel to receiving side of route and formation of encryption/decryption keys at receiving and transmission sides of route by way of hashing initial and decrypted sequences with use of function of hashing of sequences at transmitting side of route, erasure of initial and decrypted sequences. EFFECT: increased stability of formed encryption/decryption keys. 10 l, 29 dwg