Encoding algorithm by blocks having a safe robust against a cryptographic analysis differential, a cryptographic analysis and a linear differential cryptographic analysis of the order of more high

摘要

The present invention relates to an encoding algorithm by blocks based on the encoding algorithm by blocks of a feistel scheme, type (or similar to an algorithm of the). Usually, the safety of the encoding algorithm by blocks of type feistel scheme, depends on the structure of its function of a turn. More particularly, the present invention relates to the structure of a function of a turn of the encoding algorithm by blocks of type feistel scheme, in the case where the data block of the input of a turn, is divided into blocks of 8 bits, and where the - blocks 1 are provided, with the output data combined of the box, s, in a pack size of 256 × 8, except for the first in the - input block of data. The first - the data block is directly supplied to the first case is made to rotate on 8 bits, the data block of the total output, after these steps, and this result is thus turned constitutes the output of the function of a turn.