Research And Realization On Finance Smartcard Cryptograghy

As a new information carrier, the smartcard is applied in finance and telegraphy field. Although the design of the smartcard is considered in physical security and business security, in the period of the smartcard, the attacker can still destroy the authentication process and analyze business data related to the smartcard. Algorithm in finance smartcard concluded the RSA using in the authentication process between the smartcard and equipment and DES using in the business process. But on the one hand DES has short key and fall under the difference and linearity analysis, and the business data are easy to crack by using DES. On the other hand, in order to improve efficiency and reduce the mistake of smartcard system, we have to improve the speed of DES. The article aimed at the deficiency of DES, and improved the rate and intensity of it. Through the comparison of DES and improved DES, proved the improved DES is more adaptive in smartcard than DES.Frist, the article discuss the technology of the smartcard, including the operating system and international standard and the cryptography of the smartcard. Second discuss the fake randomicity theory, and some ways to produce fake randomicity sequence. Third, in order to guarantee the security of business data, using the sequence encryption and grouping encryption system, and put forward the DES of linearity feedback shift register, and give the model, description and theory analysis of the algorithm. Fourth, construct the S box, and it satisfy the nonlinearity and not to destroy the security of DES, in the other way it has the same operation result as the S box. The cryptography not only assures the security of the DES, but also improves the speed of it.