On the hidden discrete logarithm for some polynomial stream ciphers

The paper is devoted to the special key management algorithm for the stream ciphers defined in via finite automata corresponding to the family of directed algebraic graphs of high girth and two affine transformation. Security of the key based on the complexity of the discrete logarithm problem. It has additional heuristic security because of the ldquohidden baserdquo and ldquohidden valuerdquo of the discrete logarithm function. We consider the heuristic evaluation of the complexity for different attack by the adversary on our private key cipher. The detailed description of the whole algorithm is given. Implemented software package has been used for the evaluation of mixing properties and speed of the private key encryption.