Patent ID: 8837719
Filing Date: 2014-09-16
Classification: G09C,H04L

Abstract:
1. A cryptographic method by a pseudo-random generator of generating a current value for a state vector of size k corresponding to a current iteration of a pseudo-random data sequence formed by a succession of values for the state vector generated iteratively from an initial value of the state vector, the method comprising: obtaining, with a processing device, a current intermediate value calculated from a preceding value of the state vector generated in a previous iteration; forming, with the processing device, a permutation key by selecting d bits from a first intermediate vector of size k, wherein d is less than or equal to k and the first intermediate vector is formed from the preceding value of the state vector in which a section has been replaced by the current intermediate value; determining, with the processing device, d permutations, each of size k successively applying, with the processing device, each of the permutations to a provisional vector of size k determining, with the processing device, the current value of the state vector from at least one section of said result vector.