A New Chaotic Mirror-Like Image Encryption Algorithm and Its VLSI Architecture

摘要

The basic ideas of the proposed image encryption techniques can be classified into three major types: position permutation, value transformation, and the combination of the first two. The advantage of the position permutation algorithms is their potential to be integrated with a lossy still image encryption scheme without extra distortion in the decryption and decompression results. However, the major problems with position permutation algorithms are a high computational complexity and a high hardware cost, since a different permutation relation is required for each image. To overcome these problems, a new chaotic mirror-like image encryption (CMLIE) algorithm belonging to the category of the position permutation is proposed in this paper. Based on a binary sequence generated from a chaotic system, image pixels are rearranged according to the defined swapping operation with a parameter controlled by the binary sequence. The features of low computational complexity, high security, and the absence of distortions will be analyzed in detail. In order to implement the system, its VLSI architecture of low hardware cost and high feasibility for VLSI implementation is also designed. Moreover, based on a look-up table generated by the CMLIE algorithm, the architectures integrating the CMLIE algorithm with JPEG and MPEG are also proposed. Finally, the encrypted image is simulated and its fractal dimension is computed to demonstrate the effectiveness of the proposed scheme.