Design of Pseudo-Random Bit Generator Based on Chaotic Maps

In order to solve the problem of degradation of dynamical properties caused by finite states of computer, a new binary stream-cipher algorithm based on dual one-dimensional chaotic maps is proposed in this paper. In the process of generation, we employ a parameter of one chaotic map to perturb the other chaotic map's trajectory to lengthen the cycle-length of the other chaotic map's trajectory. In addition, we design a nonlinear principle to generate a pseudo-random chaotic bit sequence as key stream. Statistic proprieties show that the sequence is of high randomness.