Security Research Based On Chaotic Block Cipher

Chaos system has lots of excellent properties, such as sensitive to initial conditions and control parameters, pseudo-random property and unpredictability to the chaos rail, ergodicity, mixing and exactness. These excellent properties are consistent with the requirements of cryptography:produce pseudo-random signal, confusion and diffusion, difficult to predict the keys. Now chaotic cryptography has gradually developed into an important branch of modern cryptography. It has become a research hotspot of cryptography to construct cryptographic algorithm by taking use of the excellent properties of chaotic system. Therefore, the security analysis based on chaotic cryptography has become the top priority.The author has seriously studied the design criteria and performance analysis of block cipher, conducted an in-depth research of differential cryptanalysis and linear cryptanalysis. Based on the example analyses of DES, AES and other traditional block ciphers, the security analysis to a new chaotic block cipher has been proposed. As the uncertainty and unpredictability of the dynamic S-box, differential cryptanalysis and linear cryptanalysis to the cryptographic algorithm has been divided into two cases: fixed S-box and dynamic S-box. The result shows that compared to traditional block cipher, the chaotic block cipher can be more effective against differential cryptanalysis, linear cryptanalysis. Then the algorithm is implemented by the FPGA development board. The simulation test result shows that the S-box generated by this algorithm has good performance, the distribution of the cipher text is uniform and random, but the efficiency needs to be improved. In all, this algorithm has certain viability.