On the cryptographic properties of algorithms accompanying the applications of standards GOST R 34.11-2012 and GOST R 34.10-2012

For a number of commonly accepted models of eavesdropper the cryptographic properties of the algorithms accompanying the standards GOST R 34.11-2012 and GOST R 34.10-2012 are justified, namely, the algorithm generating the message autentication codes, algorithms generating pseudorandom sequences and key exchange algorithm. The conclusions on the security of these algorithms are based on the properties of the GOST R 34.11-2012 algorithm and on the classical complexity-theoretical problems (decisional and computational Diffie – Hellman problems).