Virtual Optical Encryption System Based On Coupling Sawtooth Spatiotemporal Chaos

With the rapid development of global information technology, a glut of information istransmitted on the Internet all the time. Whether individuals or companies and even countries havebenefited from computer network.Meanwhile, the security problems brought by computer networkalso have being noted. Therefore, ensuring the security of the computer network has increasinglybecome a serious issue and the direct and effective way is to encrypt the information.As a new technology of information security, compared to traditional cryptography andinformation security, optical encryption inherits the advantages of modern optical technology andtraditional information encryption with the capabilities of processing parallel data and largeamounts of informatioan. What’s more, it also has advantages of multiple dimension, high degree offreedom and robustness. Thus, optical encryption has attracted wide attention.In recent years, based-on optical encryption, by using the computer algorithms and software tosimulate data processing, people proposes virtual optical encryption making it possible to use theoptical encryption system in applications. Optical encryption uses a two-dimensional random phasemask as the key and virtual optical encryption uses a two-dimensional random matrix as thetemplate key. It has a large keyspace and improves the security of the system, but the me cost ofstorage, management and transport is high. In this thesis, with the properties of chaotic system ofhighly sensitive initial conditions and a large number of non-related pseudo-random sequences, thenew optical encryption system is proposed by using a random phase mask based on couplingsawtooth chaotic map. The method uses three parameters instead of random phase mask andreduces the memory of random phase mask. The simulation results indicate that the new encryptionsystem has a large keyspace and can resist brute force attacks to crack it.