The Design Of Chaotic Key System Based On FPGA

With the rapid development of the communication technology and computer technology, the global information integration has become an inevitable trend. But in the dissemination process, information could be affected by the illegal eavesdropping and destruction, which may lead to immeasurable loss, so that the information security has become a widespread concern. But chaos system is a kind of very effective encryption technology means. How to use the chaotic system to produce pseudo-random sequence with high safety and good statistical performance is the issue of the information security field in the world.This thesis discusses the design and implementation of the chaotic key system based on FPGA, in this thesis it mainly analyzes the system from three aspects: algorithm design and simulation, hardware implementation and software design.(1)In the algorithm design, the cryptography, chaos theory and some basic concepts and methods of the chaotic flow encryption technology are firstly introduced. This article chooses piecewise linear mapping as the starting point of the study to design a pseudorandom sequence algorithm based on multi-chaotic-system. In order to avoid degradation of chaotic system in digital environment, disturbing system variables, disturbing system parameters and chaotic system concatenation and adding aid key are used to improve chaotic systems.(2)In terms of hardware design, the thesis discussed the basic construction of FPGA, the verilog implementation and simulation of each module of chaotic key system and the design of hardware implementation platform. Hardware platform is consisted of four parts, ie. power supply circuit, the FPGA configuration circuit module, USB interface circuit module and SDRAM circuit module. The basic circuit design is also illustrated in the thesis.(3) In the software design, this thesis mainly introduced the design of firmware procedures, driver and human machine interface.The simulation analysis of the algorithm and the encryption results show that the keys generated by the chaotic algorthm has some advantages such as high signal complexity, large key space, perfect random property and so on. Through simulating the verilog module with Modelsim, it can be seen, the implementation of chaotic system is quite right. In addition, the hardware enviroment and application interface reach the expected requirements.