Security analysis of a multiple pseudorandom-bit generator based on a spatiotemporal chaotic map

In this paper we analyse the security of a multiple pseudorandom-bit generator based on the coupled map lattice and suggest an improved model. Utilizing the error function attack, the multiple pseudorandom-bit generators which can be realized by the three digitization methods are analysed and the effective key spaces are estimated. We suggest an improved multiple pseudorandom-bit generator with 128-bit secret key, and analyse the key sensitivity and statistical properties of the system.