METHOD OF CODING OF BINARY INFORMATION AND DEVICE FOR ITS REALIZATION Russian patent published in 1997 - IPC

FIELD: cryptography at arrangement of devices of commercial closed communication. SUBSTANCE: an N-bit secret key is formed, with the aid of which a flow code is formed, summation being modulo 2 with an information text; the flow code is formed as K groups with N bits in each, where k N - length of the text being processed. The first group of the flow code is formed by raising the N-bit secret key to the n power to modulo P, and the second group of the flow code is formed by raising the N-bit code of the first group of the flow code to the n power to modulo P, where - number of least-significant bits of the secret key with 1<n<<N<P-1, and each subsequent i group of the flow code, where i=3,4,...k, is formed by raising the n-bit code of the i-1 group of the flow code to the m power to modulo P, where m-number of least-significant bits of the i-2 group of the flow code, m=n; prior to taking a sum to modulo 2, in each group of the K groups of the formed flow code the bits are mixed in an accidental manner and memorized. The device for realization of the method uses unit 1 for raising to n power to modulo P, power register 2, secret key register 3, key group register 4, sequence bit mixing unit 5, first and second modulo 2 adders 6 and 7, key 8, control unit 9, serial- alternate registers 10₁-10₄, OR gate 11 and AND gates 12 12₁-12₃. EFFECT: enhanced safety of information in computer commercial communication systems. 2 cl, 1 dwg