PROCEDURE FORMING ENCODING/DECODING KEY Russian patent published in 2001 - IPC

FIELD: cryptography. SUBSTANCE: invention can be used as individual component in construction of symmetrical cryptographic systems designed to transmit encoded speech, sound, TV and other messages. Procedure forming encoding/decoding key provides for formation of initial sequence on transmitting side of route, its encoding, extraction of encoded initial sequence of block of test symbols, its transmission over forward communication channel free of errors to receiving side of route, formation of decoded sequence at receiving side of route, formation of hashing function of sequences at transmitting side of route, its transmission over forward communication channel free of errors to receiving side of route and formation of encoding/decoding keys at transmitting and receiving sides of route by way of hashing initial and decoded sequences in accordance with hashing function of sequences formed at transmitting side of route. EFFECT: formation of encoding/decoding key ensuring increased resistance of formed encoding/decoding key to compromise on side of violator. 10 cl, 29 dwg