Patent ID: 6314187
Filing Date: 2001-11-06
Classification: H04L

Abstract:
A method for encrypting or decrypting a sequence of successive data words of length M in a data communications device, comprising executing an algorithm in which a sequence of quasi-random encryption words of length M is generated from predetermined start values by performing operations in a finite group GF(2.sup.N), and in which a respective one of the encryption words is combined with a respective one of the data words, wherein the algorithm is based on a Galois field of R state variables x and R constant, predetermined factors p which are addressed by L indices I, with L<R wherein the start values for the state variables x and the indices I for the algorithm are uniquely determined by means of an initialization method wherein the start values are generated from predetermined initialization values k in a quasi-random manner by performing operations in a finite group GF(2.sup.Q).