Akey Stream Algorithm Based on GEP's Evolving Boolean Function

Key stream generator is a core part of Stream cipher.In accordance with structural thought of nonlinear combination key stream generator,a new RSA-LFSR key stream generator is proposed in this paper.The random sequences from the generator generated in combining of RSA and LFSR algorithm make combining operations with evolving Boolean function based on gene expression programming (GEP),and output key stream.Meanwhile,safety inspections are made to the different length key sequences generated through RSA-LFSR key stream generator.Through runs test,frequency inspection, sequential test and the calculation of linear complexity,the experiments demonstrate that RSA-LFSR key stream generator is more superiority and security than traditional nonlinear combination key generator.