Research On Adaptive Image Encryption Algorithm

The modern society has entered the information age. With the development of globalization network technology, the way people transfer information has been completely changed, Internet technology has become an integral part of people’s life. These techniques make our work and life more convenient, while with the increased of flow of information in network, the privacy of people are nearly under the attack. Therefore,transfer information Securely in the network has become an important topic which in the study of large companies and research institutions.In today’s society, digital image are widely used in various fields. Use the traditional encryption technique, such as the IDEA and AES, to the image encryption has certain defects. Because the traditional encryption algorithm is mainly designed for one-dimensional data stream, without considering the characteristics of two-dimensional images, such as the space order, visual redundancy, correlation. This makes the traditional encryption algorithm take too long time when encrypted digital image. Scholar Chen and others proposes a new Self-Adaptive image scrambling cryptographic algorithm in the paper’A Self-Adaptive Algorithm on Image Encryption’. They proved the encrypted image can effectively prevent the known plaintext attack. At the same time, the algorithm also has excellent integrity protection function, can be used for image authentication. But as scholars gradually research, self-adaptive algorithm on amage encryption did a lot of impact on security. Therefore, in order to prevent the security threat of self-adaptive algorithm on amage encryption, we propose some security improvements.This paper main research content as follows:(1) The first part includes chapter one and two. This part mainly introduces the origin and history of cryptography, and the research status of digital image encryption technology at home and abroad, introduced the mathematical basic knowledge and cryptography basic knowledge needed in this paper.(2) The second part is chapter three. This part introduces the details of self-adaptive algorithm on amage encryption, and puts forward two kinds of chosen-plaintext attack and statistical attack, find the threats in terms of security of self-adaptive algorithm on image encryption. (3) The third part includes chapter four five six and seven. In this part, we propose some improved algorithm respectively aim at the security threat of self-adaptive algorithm on image encryption. In chapter four, we propose an improved algorithm which based on the Josephus ergodicity aim at two kinds of chosen-plaintext attack. In chapter five, we propose an improved algorithm which based on cyclic shift aim at statistical attack. In chapter six we propose an improved algorithm combined with advantages of the two kinds of improved algorithm which we propose at the previous two chapters advantages. The analysis results show that the improved algorithm in the form of combination can effectively improve the security of the self-adaptive algorithm on image encryption. In chapter seven we propose two kind of improved algorithms which based on the S-box of DES algorithm and the S-box of DES algorithm. Then we proved them are available, and analyzed their security.