Research On Key Technologies Of Quantum Image Security

Computer plays a more and more important role in the production and life of modernpeople. With the development of computer and internet, especially the growing problemsof large storage and large data, the traditional computer is far to satisfy the requirement ofpeople on the storage capacity and processing speed. In this situation, quantum computerwill solve this problem because of its natural parallel processing ability. Image media is avery important representation pattern for information production, transmission and anal-ysis. In traditional computer field, the protection of image has extensive application incovert communication and media authentication. In the quantum era, the representationand security protection of image will still be a key problem. However, just as the explo-ration stage of quantum computer, the research of quantum image locates at the starting,and many concepts, theories and applied models are needed to further completed. Thisthesis targets quantum image and explores the theories and realization methods of quan-tum image representation, security protection and authentication to improve the securityprotection techniques of quantum image.We have introduced the related concepts of quantum image representation and se-curity at first. Then, we have analyzed the problems faced by quantum image security.Finally, we have proposed new methods and new approaches for quantum image authenti-cation and secure communication. Thus, the security and applicability of quantum imagehave remarkable improvement. The main contributions and innovations of this thesis aredemonstrated as follows:(1) We have build a universal programming mathematical model for quantum imagewatermarking based on quantum transform. In the model, we have introduced a dynamicvector instead of a normal parameter to control the embedding strength of watermarking.The programming model takes that the computation process should keep normalized stateas constraint and takes that the change state of quantum states representing carrier imagebefore and after embedding watermark should have fewer magnitude as target function.Under the model, we have designed two quantum image watermarking algorithms basedon quantum wavelet transform and Hadamard transform, respectively. They have biggerembedding capacity and better visual effect.(2) We have proposed a novel quantum image encryption algorithm based on per-mutation and dif fusion operations. We have permutated quantum image using restrictedgeometric transformations. Then, to make the encrypted image more secure, we haveresearched the method and realization of restricted gray transformations. Based on therestricted gray transformations, we have dif fused the quantum image to a securer pattern.The algorithm improves the security of encrypted quantum image.(3) We have explored the concept of quantum image sharing techniques. We haveproposed a quantum image secret sharing scheme based on measurement and strip. Thesharing scheme has the following advantages: no second encoding, no pixel expansionand the quantum image state’s retentivity, which provides a new method for quantumimage security.(4) We have researched the security algorithms for color quantum image. First, amulti-channel quantum image representation is proposed based on phase transform andthe preparation process is given. Then, we have designed the elementary transformationsunder this representation. Finally, we have researched the schemes of watermarking,encryption and secret sharing methods for color quantum image.