METHOD FOR BLOCK CONVERSION OF DIGITAL DATA BASED ON SHIFT REGISTER EIGHT SYMBOLS LONG WITH 32-BIT CELLS AND WITH THREE FEEDBACKS Russian patent published in 2023 - IPC H04L9/06 

FIELD: information security.

SUBSTANCE: round key generator performs round key generation and uses a unique round key in each round. The input data is split into 256-bit data blocks. Before conversion, each 256-bit data block is divided into eight 32-bit subblocks X0, X1, ..., X7, which are converted in turn during at least 16 conversion rounds, while the conversion round is as follows - for subblocks X1, X3 , X4, X6, X7 and three round subkeys q1, q2, q3 determined in accordance with the key schedule, three values of the feedback functions f(S, q1), f(S, q2), f(S, q3) are calculated, where S=X1+X3+X4+X6+X7 (mod 2³²), and the obtained values of the feedback functions are added to the subblocks X2, X5, X0 using the operation of bitwise summation modulo 2, and the initial values f(S, q1), f(S, q2), f(S, q3) are formed by summing modulo 2³² values of subblocks X1, X3, X4, X6, X7 and round subkeys q1, q2, q3, after which cyclic shift by nineteen positions in the direction of the most significant bits is performed using the cyclic shift registers, after each round of encryption, the subblocks are transformed by cyclic shifting to the left.

EFFECT: reduction in computational costs for execution of information block processing procedure, an increase in the encryption speed and an increase in resistance to sequential sampling methods, differential cryptoanalysis and other methods associated with them.

1 cl, 4 dwg, 2 tbl