Aflexibleandsecureimagecompressioncodingal.doc

A image compression and encryption scheme based on arithmetic coding( Based on secure arithmetic coding, an efficient image data compression and encryption scheme is proposed. Firstly, the feedforward–feedback nonlinear dynamic filter (FFNDF) is employed to generate pseudorandom sequences which determine the mapping the interval position in the process of arithmetic coding. Then, by encoding the bits obtained from different SPIHT passes using adaptive secure arithmetic coding, we obtain a flexible secure image compression and coding bitstream. Of course, the encryption scheme accommodates features of progressive coding in SPIHT. Therefore, total encryption, selective encryption and conditional access are also discussed in the scheme, which expand the various applications. Theoretical analysis and experimental results show that the scheme has good cryptographic security and perceptual security, and it does not affect the compression efficiency apparently. Keywords: chaotic cryptanalysis; image encryption; FFNDF; random arithmetic coding 1. Introduction With the rapid development of digital image contents in the wired and wireless communication technologies, the image encryption and copyright protection has became a serious problem and attracted many researchers’ interests. For one hand, traditional encryption schemes are not suitable for image applications since computational complexity in the block-based encryption techniques such as DES and AES is high especially for portable devices. For the other hand, the encryption scheme can preserve compression properties as many as possible for transmission. Therefore, it is desirable to develop an image encryption technique in the compressed domain. Image encryption using chaotic theory provides a potential solution and researchers have presented many related algorithms[1]. A common architecture of existing chaos-based image encryption schemes is mainly based on pixel permutation and diffusion in the spatial