METHOD FOR GENERATION OF ENCRYPTION/DECRYPTION KEY Russian patent published in 2007 - IPC H04L9/14 

FIELD: cryptography, possible use as separate element during construction of symmetric cryptographic systems, meant for transferring encrypted speech, sound, television and other messages.

SUBSTANCE: for realization of method at transferring side of communication guiding a random series is generated in form of three blocks X₁,X₂,X₃ with lengths of k₁,k₂,k₃ respectively. Series is transferred with errors via communication channel (Y₁,Y₂,Y₃ - received blocks). Blocks of checking symbols C₁ and C₂ are formed for blocks X₁ and X₂. Message S_C1+C2 is formed by concatenating blocks C₁ and C₂. Authenticator w for received message is formed, using a checking code and block Y₃. Blocks of checking symbols C₁ and C₂ are selected from received message S_C1+C2. from blocks Y₁, Y₂ received in advance via communication channel with errors and blocks of checking symbols C₁ and C₂ decoded blocks . Encryption/decryption keys are generated at receiving and transferring communication guiding sides by hashing block X₁ at transferring communication guiding side and decoded block at receiving communication guiding side.

EFFECT: decreased time consumed by generation of encryption/decryption key, increased resistance of generated encryption/decryption key to discrediting by a violator.

6 cl, 37 dwg