Method for processing a digital signal in a so-called secure communication system and use of this method for access control and/or binary signature

The present invention relates to a method for processing a digital signal in the k dimension such that, in a so-called secure communication system, a digital signal (y) at the output cannot be estimated from a digital signal (x) at the input, the method comprising executing a one-way function supplying a digital signal (x) to the device. The method comprises the following steps: - providing a digital signal x at the input to a circuit C(1,2) which provides as output a digital signal x'' of n dimension acceptable to a one-way function and providing a signal x'' from circuit C(1,2) to a circuit providing a digital signal y as output by executing a one-way function. The invention applies in particular to so-called secure communication systems.