The Study On The Application Of Quantum Random Walk In Image Encryption

With the rapid development of communication technology such as computer and Internet, how to protect multimedia data especially to protect the security of image data has become increasingly important. The emergency of image encryption technology is a good solution to these problems. In recent years, chaos theory is widely used in the field of image encryption, but the existing classical chaotic systems are not perfect, such as short cyclical, which makes the image encryption algorithm based on the classical chaotic maps exist security flaws easily. Quantum random walk(QW) is a new type of quantum computing model proposed in recent years, and it has some similar properties with chaos, the dual character of highly non-linear and parallel computing makes QW have more advantages than the existing chaos theory. Therefore, the image encryption based on QW research has important theoretical and practical significance.This paper based on the QW to study image encryption, the main research work and contributions include the following aspects:(1) We construct a pseudo-random number generator(PRNG) based on one-dimensional two-particle discrete QW. Using a variety of randomness detection tools(such as NIST, DIEHARD, ENT, Test U01) conduct random testing, the produced bit sequence pass the random testing, and in some aspects superior to the existing pseudo-random number generator, such as non-periodic, statistical complexity, entropy, the computation time, the key space and the recurrence.(2) We construct a gray image encryption based on one-dimensional two-particle discrete QW. Through compare with the existing image encryption scheme shows that the indicators of key space, plaintext sensitivity, key sensitivity, correlation, entropy of image encryption algorithm based on the discrete QW are better than the existing image encryption scheme.(3) We put forward a novel color image encryption scheme based on one-dimensional two-particle discrete QW. The general color image encryption scheme is just to encrypt the three color componets respectively, but ignore the link between them. Our algorithm global diffusion the combination of the three components of color image, and enhance the links between the three components, rather than individually encrypt each component, the security of our proposed algorithm is higher.