Verfahren zur Verarbeitung eines digitalen Signals in solcher Weise, dass das Ausgangs- nicht vom Eingangssignal abgeleitet werden kann, und Verwendung des Verfahrens zur Zugriffssteuerung und/oder digitaler Unterschrift

摘要

The method involves use of a scrambling circuit (1) which receives a digital input signal (x) of dimensionality, k, and sends a signal to a formatting circuit (2) to give a digital signal (x") of dimensionality, n, acceptable to the function. The formatting circuit can be a permutation generation circuit applied to a secret key signal (S) of dimension, n, and Hamming weighting, d, lexicographical sort. Alternatively the secret key may act on a pseudo-random generator with a digital input and an output which is a signal of n dimensions with heavy Hamming weighting, d. The output (y) is obtained using a function obtained by multiplying a binary digital signal by an m x n binary matrix where n is the number of columns.