Research And Analysis Of Image Encryption Algorithms In Spatial Domain Based On Self-adaptive Wave Transmission

With the development of computing and network technology, multimedia data are used more and more widely. So,the security of multimedia data draws increasingly attention. Cryptography is the major method to resolve it. However,contrast to texts, multimedia contents contain huge volume of data, which makes their encryption become very slow and power-consuming. This paper focuses on the approaches to design a secure and fast algorithm for image in spatial domain. Some of the conclusions and contribution of this paper are listed as follows.①A brief description of the basic theory for image encryption in spatial domain is presented,including basic theory of cryptology, basic ideas of image encryption, performance indexes, diffusion techniques and basic requirement of parallel image encryption.②Analysis and summarization of the existing classical image encryption in spatial domain. Point out its features, advantages, disadvantages as well as where its weakness lies in.③Put up with the idea of wave transmission, that is, encrypting a image by simulating the transmission of discrete waves on it. Provide the details of realizing it. Carry out a thorough analysis on it to find its advantages,disadvantages and the way to make up with its weakness.④By combining the idea of wave transmission with self-adaptive encryption according to its feature,the image encryption algorithm based on self-adaptive wave transmission is proposed. The algorithm first extracts some certain information from a part of the image after doing partitioning; combine them with keys to control the three parameters of four sin waves. Then, using the four waves to encrypt the left part from which none information is extracted. At last, the unencrypted part is encrypted with the encrypted part using the same method. The detailed encryption and decryption progress as well as its parallelized frame are given. Simulation results for a gray-level and a color image and comparison with other typical algorithms have demonstrated the high performance on the sensitivity, speed, and security of the proposed algorithm.Finally, there comes the conclusion of this dissertation. Some disadvantages and further work are also given.