Study On Encryption And Anti-counterfeiting Technique Based On Random Phase Encoding Algorithm

The development at full speed of the information technology brings the worldwide change with the arrival of information ages. The information network system has become the necessary infrastructure of each social realm. It provides powerful technical support for the rapid development of information industry and plays an important role to promote the progress in informationization of the whole society with the network project and "Gold Block" project successive launching in China. It improves the modernized management level and the people's living quality.With the rapid development of science and technology, however, more and more fraud cases on the network and some important cards, such as a passport, a credit card, and other IDs are reported recently. It has produced important economic losses and bad effect to society in our country. Therefore, the effective encryption and auti-counterfeiting technique should be studied and developed, and is also a very important research topic in information security.Cryptography is the kernel of information security technology. The highly intensive encipher algorithm provides important guarantee for protecting the valuable data and preventing the crime of computer network. Optical information processing techniques for encrypting and security data have generated considerable interest in the optics community in the last one decade. In this thesis, the theory for the random phase encoding technique is discussed deeply, and the robustness and security of the optical system are analyzed and improved. The proposed algorithms can effectively resist known-plaintext attack and be easily realized with hardware, and the security is improved greatly. The corresponding solutions for certificate anti-counterfeit systems, identity authentication and network security are proposed. The main research content of this paper includes:(1) The optical scalar diffraction theory and the attribute of the Fourier lens are discussed on the basis of Kirchhoff diffraction formula. The encoding method and realization for computer generated hologram of Fourier transform and kinoform are illustrated, and provide a theoretical and technical preparation for optical realization of random phase encoding technique.(2) The encoding algorithm is introduced in detail, and the security and robustness for double random-phase encoding technique are analyzed in particular. Based on the optical...