Design And Implementation Of Network Encryption Machine Based On Chaotic Algorithm

At the coming of the 21 st century, information resources play a significant role in social life. The security problems of Internet attract extensive attention, because it is an important platform for information sharing. Once the information leakage would cause serious damage to individuals and even the country, so the research of network information security is particularly important and urgent.This paper designs a network encryption machine based on embedded technology and chaotic sequence encryption algorithm. In the design of hardware, circuit adopted structure of core-board with baseboard. Core-board is a six layer board based on ARM11 processor. Besides, peripheral circuit of baseboard is designed, including DM9000 Ethernet micro-controller module, JTAG module, power module and serial module. In software programming, socket network program technique is adopted based on C/S model. Sequence encryption algorithm is used for encryption of network data, which possesses some advantages such as simple implementation, high encryption and decryption speed and wide range of application. Random sequence generator of the paper is generated by one-dimensional Logistic mapping, because chaotic signal has many good character such as pseudo randomness, initial value sensitivity and noise-like character.But Logistic chaotic signal in the process of iteration and quantify influenced by limited precision of processor. Therefore, 0/1 digital sequences appear a kind of phenomenon of similar-short period and reduce the security of the encryption system. A modified encryption algorithm is proposed with the purpose of surmount these deficiencies, which combines Logistic mapping with Arnold transformation to generate a new random sequence generator. At the same time, some comparative experiments are done about autocorrelation and spectral analysis of new and old sequences. Experimental results indicate that modified chaotic sequences has a good pseudo-random property and has the ability to meet the requirements of confidential communication.In this paper, the design of network encryption machine combines chaotic sequence encryption algorithm with embedded technique, which possesses some merits such as high security, fast encryption speed and easy installation. Besides, it can guarantee security transmission of information resources of Internet user.