Cryptanalysis of Some Self-Synchronous Chaotic Stream Ciphers and Their Improved Schemes

In this paper, a cryptanalysis method that combines chosen-ciphertext attack with divide-and-conquer by traversing multiple nonzero component initial conditions (DCA-TMNCIC) is proposed. The used for security analysis of [Formula: see text]-D ([Formula: text]) self-synchronous chaotic stream ciphers employ product two variables and three SCSC-2 SCSC-3), taking 3-D as typical example cryptanalysis. For resisting the combinational effect DCA-TMNCIC, several improved cipher schemes are designed, including SCSC based on nonlinear nominal system (3-D SCSC-NNS) sinusoidal modulation SCSC-SM text])). Theoretical validates schemes.