Research On Transmission Technology Based On Key Exchange And Chaotic Sequence Cryptography

China is in the mutual promotion tide of the information technology and economic globalization, and it is deeply affected by the Internet. Network security and privacy information protection indeed affect the whole areas. If no information security, there is no national security. So it is very necessary to own ingenious technology, but we are also relatively backward in terms of innovation, it’s no doubt to research cryptosystems and cryptographic chip with independent intellectual property rights.In this paper, the design of a hybrid scheme combining the RSA public key algorithm and chaotic sequence encryption is finished in FPGA hardware, which achieves double-secure transmission system of key and data encryption. Encryption system also includes a main controller design, the external communication module design, the cache module design, and the nearly realizes data integrity, security, and correct transmission. When studying this transmission technology, uses a top-down methodology, and VHDL hardware description language to achieve each of the various sub-modules, and ultimately integrated into a complete encryption systems. The core of the system is chaotic stream cipher to encrypt data and RSA public key encryption algorithm to encrypt the initial key, achieving a combination of public and private keys, to reach a balance of speed and security.In this paper, we compare the Logistic and Tent chaotic sequence characteristics, including autocorrelation properties, run characteristics, balance and hardware resource utilization. In the comparing process, the concept of relevant characteristics of critical line width is proposed, so the differences of the chaotic sequences are apparent; we can determine the Logistic sequence has superior performance, less resource-intensive, more in line with the needs of hardware encryption system.Difficulty of the design is FPGA hardware implementation of RSA public key algorithm, which protects the initial key not to be attacked. In the RSA algorithm module, firstly study deeply number theory which is a basic knowledge of RSA algorithm and Euclid and its extension theorem. They all provide ideas for the subsequent RSA parameters generation, modular multiplication, modular exponentiation algorithm analysis and VHDL programming. Before hardware implementation, uses Matlab simulate RSA encryption process firstly, so that the whole design is more careful. Finally achieve the top-level design, public key judgment module design, the private key generation module design and RSA encryption and decryption module in FPGA design.This paper, the full encryption system all achieve on hardware platform FPGA. Hardware encryption has the advantages of fast speed and high security. This is a major trend in future for encryption product applications and cryptography practice.