Dsp-based Data Encryption Technology Research

With the rapid development of the information technology, what people communicate with each other became more and more. So users are in urgently need of security at the same time. The key to the information security is cipher technology, which realize the information's confidentiality , integrality and non- repudiation. In the recent years, most countries pay more and more attention to cryptography, and the development of cipher technology grow rapidly. The cryptography can be divided into two area, private-key cryptography and public-key cryptography. With the superiority of digital signature, authentication and secret-key management, the public-key cryptography has a wide application across the world. RSA just is a representative. RSA meets especially the need of modern secret communication because of its simple algorithm, excellent cipher performance, and without the trouble from manage key as usual.In RSA cryptosystem, modular multiplication is core section. Montgomery's algorithm is one of the most efficient algorithm implementing modular multiplication in RSA cryptosystem. For the reason of fast encryption, it is often required to realize cryptographic algorithms in hardware. A data encryption card based on TMS320C6713 processor and PCI bus is designed. In this paper, RSA and Montgomery algorithm are further discussed. Based on the architecture characteristic of TI TMS320C6713 DSP, this paper provides an improved Montgomery modular multiplication algorithm, and it is implemented in RSA cryptosystem.The data encryption card, designed in the paper, can be widely used in all kinds of data encryption systems. Moreover, it also can be added up into all kinds of encryption algorithms to realize various social demands, if needed.