Simultaneous Arithmetic Coding and Encryption Using Chaotic Maps

Based on the observation that iterating a skew tent map reversely is equivalent to arithmetic coding, a simultaneous compression and encryption scheme is proposed in which the chaotic map model for arithmetic coding is determined by a secret key and keeps changing. Moreover, the compressed sequence is masked by a pseudorandom keystream generated by another chaotic map. This two-level protection enhances its security level, which results in high key and plaintext sensitivities. The compression performance of our scheme is comparable with arithmetic coding and approaches Shannon's entropy limit.