On Iris Unitary Transform And Image Cryptogram Method In Iris Unitary Transform Domain

Information security as a main part of modern national security, in particular theimportance and urgency of image information security are becoming increasinglyprominent. Demanding for the security of the image information’s acquisition, storage,transmission, processing and application has become more and more urgent and moreand more important. In this paper, we introduce iris image into the research of imagecryptosystem, not only structure iris unitary transform which take iris image as thecore parameters, but also create image cryptosystem in iris unitary transform domain,analyze and demonstrate the security, reliability and practicability of digital imageencryption method in iris unitary transform domain. Those studies provide a neweffective way and method for the research of image information security, and are ofimportant theoretical significance and practical value for modern national security.Research contents of this paper include the following parts.First, we establish iris unitary transform theory of one dimension and two-dimensionform, study the basic properties of iris unitary transform which take iris image as thecore parameters, establish numerical algorithm of discrete iris unitary transform ofdigital image, which lay the theoretical foundation for applying iris image informationto the research of image cryptosystem.Second, combined with random variable theory, chaos iteration theory and iris unitarytransformation theory, we construct image cryptosystem which take iris image as themain encryption key in iris unitary transform domain, study detailedly the encryptionand decryption process of this image cryptosystem and its implementation method,keys space, the statistical characteristics and random characteristics of keys.Then, this paper studies the randomness and establishes a random theory of this imagecryptosystem. It has been analyzed and proved this image cryptosystem is stochastic.In this stochastic image cryptosystem, anyone original plaintext image willscorrespond to a large number of differently possible ciphertext images which arestatistically irrelevant. Fourth, the theoretical security and practical security of image cryptosystem is studied.Using this image cryptosystem’s randomness, the characteristics of the composition ofthe key space and iris unitary transform theory, we analyze and set forth the resistanceability of this image cryptosystem when typical cryptanalysis or statistical randomattacks on it and the coherent ability between decrypt ciphertext and original plaintextinfluenced by random disturbance of ciphertext image and shear damage.Finally, this paper has adopted a great deal of digital simulation to demonstrateencryption and decryption process of this image cryptosystem and its security,reliability and practicability. Through the way of conclusion and discussion, wesummarize the innovative achievements obtained and discuss some questions worthyof further being studied which may improve the security of image cryptosystem. Here,all the work of this paper has been finished.