Chaos-based cryptograph incorporated with S-box algebraic operation

Error function analysis is an effective attack against chaotic cryptograph [Phys. Rev. E 66 (2002) 065202]. The basin structure of the error function is crucial for determining the security of chaotic cryptosystems. In the present Letter the basin behavior of the system used in [Phys. Rev. E 66 (2002) 065202] is analyzed in relation with the estimation of its practical security. A S-box algebraic operation is included in the chaotic cryptosystem, which considerably shrinks the basin of the error function and thus greatly enhances the practical security of the system with a little computational expense