The Design Of A Digital Image Algorithm Based On Simple Physical Models

With the rapid development of techniques of computer hardware, CloudComputing and Big Data, data security has become one of the most indispensabledemands of computer users and the Internet users these years. People concern securityat any time anywhere. With the development trend of the explosive growth of datavolume in the Internet and multi-core technique, the demands of constructing a newcryptosystem to adapt to the circumstances mentioned above are becoming more andmore urgent. Therefore, design of a cryptosystem with simplicity, parallelism andhigh-efficiency has both practical and theoretical significance. We propose a method ofconstructing a secure cryptosystem based on simple physical models.In this thesis, we investigate preliminary properties of several simple physicalmodels. We introduce the research background and current status of cryptosystemstogether with algorithm and application scenario of the classical cryptosystems whichwe have constructed already. Then we summarize and analyze each of the classicalcryptosystems, identify their common weakness.Considering the trends of hardware and the application environment of CloudComputing as well as big data, we construct a new cryptosystem to construct acryptosystem based on simple physical models. This thesis consists of four parts aslisted below:First, we examine classical encryption methods including block cipher, streamcipher and public key cipher and so on, and point out their common weakness. In orderto overcome the weakness, we need some new encryption methods.Second, we introduce in two physical models: RE model and HPP model. Thecomputing method of each model is presented. Then we revise the implementation oftwo models so as to improve their efficiency significantly.Third, we propose a method to initialize the key and to generate the round key foreach encryption round as well. We then present the detail of our proposed cryptosystembased on physical models. We also discuss the application modes of digital imageencryption algorithm.Fourth, experiments are carried to test the performance, randomness and sensitivityof the proposed encryption algorithm. Analyses and simulation demonstrate that the algorithm has advantages in security and efficiency, while supporting parallelcomputing.Finally, we’ve got a conclusion. Still, some flaws remain. Further work is alsogiven.