There are many encryption algorithms . even for one algorithm , rsa , for example , the architectures of different modular length rsa are not same . the dissertation focuses on the research and design of the reconfiguration in the encryption application using fpga 在现场可编程逻辑阵列fpga上，实现多种加密算法以及不同长度密钥的rsa算法的可重构，在目前对开展可重构计算技术在加密方面的应用基础研究和研发有自主版权的加密硬件技术有一定的意义。
This system makes full use of the security of the aes and the rsa algorithms and the fast speed of tms320c64x dsp chip . it could be widely used in finance , telecommunication , medical and insurance etc . with the development of internet and e - business , this card will has a prosperous market in the future 此系统充分利用了aes和rsa算法的安全性和tms320c64x数字信号处理芯片的计算速度快的优点，能够广泛应用于金融、电信、医疗、保险等诸多行业。
However , most of the electronic business secure protocols are subject to the limitation of export regulations . for example , only 40 bits or 56 bits of rc4 algorithm and 512 bits of rsa algorithm are permitted to export , and its source code is n ' t published 但是，国外主流的电子商务安全协议在核心密码算法上都有出口限制，如只允许40位或56位的rc4和512位的rsa算法出口等，而且协议源代码不公开，根本无法满足我国电子商务实际应用当中的安全需求。
This article will introduces the representative of the public key system and the private key system - rsa and aes algorithm . the rsa algorithm is a widely used algorithm while the aes algorithm being the substitute of the des , is regard as the encryption standard of the 21st century . it has great actual significance to make research on such two algorithms 本论文将介绍公、私钥算法的代表? rsa和aes算法，其中rsa算法是当今应用最广泛的公钥算法，而aes算法是des的替代，被称为二十一世纪的加密标准，选择这两种算法进行研究具有很强的现实意义。
The whole system can be used widely not only as an independent specific system module , but also in the embedded system with cpu control . finally , the interface between microprocessor and rsa , or between rsa and eeprom is implemented to realize the whole system function . the design of iic part is depicted with verilog hdl Rsa算法实现的软核设计在应用上具有很大的灵活性和独立性，在接口模块的配合下可以作为系统中独立的加密解密运算部件，在微处理器的控制下使用，可以作为独立的专用系统来使用。
The system give the improvements of the original otp plan and add a systematic random number and time blunt which also use ras algorithm encrypt and decrypt the user ' s current secret language by way of the service ' s public or private key when the system carry out 对原有otp方案进行了改进，在生成一次性口令因子中增加了系统随机数及系统时间，并在系统实现时使用服务器的公钥私钥对由rsa算法加密和解密每个用户的通行密语，有效地阻止攻击者进行口令窃取和字典攻击。
