An enhanced variable-length arithmetic coding and encryption scheme using chaotic maps

We enhance the simultaneous arithmetic coding and encryption scheme previously proposed by us. By encoding a block of variable number of symbols to a codeword within the length of the computation register, the operating efficiency has been substantially improved. Moreover, the compressed sequence is processed by an additional diffusion operation which strengthens the security of the original scheme by having higher key and plaintext sensitivities. Simulation results show that the enhanced scheme runs faster than the original scheme and the traditional compress-then-encrypt approach at a comparable compression performance.

► The proposed scheme performs simultaneous arithmetic coding and encryption with secret models of chaotic map.
► The operating efficiency is substantially improved with variable-length arithmetic coding using chaotic map.
► The security is enhanced by a diffusion operation and an efficient pseudorandom bitstream generator.
► The proposed scheme runs faster than our previous scheme and the traditional compress-then-encrypt approach.