An efficient hybrid chaotic image encryption scheme

Abstract

In recent years chaotic cryptography has attracted significant attraction for multimedia security. However, most of these chaotic ciphers still suffer from excessive computation for a given level of security [1-3]. In view of these, a novel scheme is proposed in this paper to encrypt digital images that has far smaller computational load. The proposed scheme is based on multiple-piecewise linear chaotic maps (m-PLCMs) and S-box, where the R, G and B channels of digital images are first segmented into low correlated frames of the appropriate length. Identical chaotic key stream is used for the various frames of the R, G and B channels of the segmented image. The reuse of the chaotic stream reduces the computational complexity by a higher factor and the combination of S-box makes it infeasible to extract the chaotic stream due to its low differential and linear probabilities. The analysis of the proposed scheme proves that it efficiently fulfills the tradeoff between security and encryption speed © 2007 Springer.