Abstract

A chaotic filter bank for computer cryptography is proposed. By encrypting and decrypting signals via a chaotic filter bank, the following advantages are enjoyed: 1) one can embed signals in different frequency bands by employing different chaotic functions; 2) the number of chaotic generators to be employed and their corresponding functions can be selected and designed in a flexible manner because perfect reconstruction does not depend on the invertibility, causality, linearity and time invariance of the corresponding chaotic functions; 3) the ratios of the subband signal powers to the chaotic subband signal powers can be easily changed by the designers and perfect reconstruction is still guaranteed no matter how small these ratios are; 4) the proposed cryptographical system can be easily adapted in the international multimedia standards, such as JPEG 2000 and MPEG4.