METHOD FOR ITERATIVE ENCRYPTION OF BIT DATA BLOCKS Russian patent published in 2004 - IPC

FIELD: electrical communications and computer engineering. SUBSTANCE: proposed method designed for encrypting bit data blocks to protect information transferred over telecommunication networks involves generation of private key incorporating R≥2 round subkeys K₁, K₂, ... K_R, where R is number of encryption rounds; division of bit data block into two subblocks and execution of R encryption rounds; rearrangement of first and second converted subblocks after each r encryption round, where r = 1, 2, R 1, first control code being shaped during each encryption round; conversion of binary vector depending on round subkey K_r; execution of direct controlled exchange operation with respect to second subblock depending on first control code; superposition of converted binary vector on second converted subblock by their addition; execution of reverse controlled exchange operation with respect to second converted subblock depending on second control code; during each encryption round first control code is generated with respect to first subblock and at the same time fixed exchange is executed and second control code is generated with respect to first converted subblock. EFFECT: enhanced encryption speed. 4 cl, 4 dwg