METHOD AND DEVICE FOR TRANSFORMING DATA WITH CONVOLUTIONAL CHARACTER AND VARIABLE OFFSETS, AND SYSTEMS USING SAME

摘要

The invention concerns a method for transforming a sequence of N original binary data (b>1<, , b>N<) representing a message, using at least a key, N being an integer greater than 1, which consists in producing a sequence (u>1<, , u>N<) of N algebraic offset values and in filling a table of N+1 lines where: the original sequence (b>1<, , b>N<) is written on the first line of the table; for each integer i included between 1 and N, on the (i +1)?th> line of the table is written an intermediate sequence of binary elements wholly or partly offset by ui columns relative to the sequence written on the first line, the intermediate sequence being, either a predetermined sequence contained in the key if the i binary data (bi) of the original sequence is equal to 1, or a sequence of zeros otherwise; and in performing an addition modulo 2, column by column, of the binary elements contained in the table.