Embedding Compression in Chaos-Based Cryptography

An algorithm for embedding compression in the Baptista-type chaotic cryptosystem is proposed. The lookup table used for encryption is determined adaptively by the probability of occurrence of plaintext symbols. As a result, more probable symbols will have a higher chance to be visited by the chaotic search trajectory. The required number of iterations is small and can be represented by a short code. The compression capability is thus achieved. Simulation results show that the compression performance on standard test files is satisfactory while the security is not compromised. Our scheme also guarantees that the ciphertext is not longer than the plaintext.