【作者】 高岩；

【导师】 程胜利；

【作者基本信息】 武汉理工大学 ， 计算机应用技术， 2002， 硕士

【摘要】 当今社会处于信息时代，随着计算机互联网络的飞速发展，整个世界被越来越紧密地联系在一起。这在为人类社会带来巨大便利的同时，也产生了一系列严重的问题，信息安全就是其中突出的一个。由于网络存在着许多重要、敏感数据，因此，信息安全已越受人们的关注，确保信息的安全性，一般通过建立数据保密管理的规章制度及采用密码学的方法来保证。 密码学是信息安全技术的核心，现代密码体制分为公钥体制和私钥体制两大类。私钥体制又称单钥体制，其加密过程和解密过程相同；公钥体制又称为双钥体制，其加、解密密钥不同，可以公开加密密钥，而仅需保密解密密钥，从而具有数字签名、鉴别等新功能，被广泛应用于金融、商业等社会生活各领域。 公钥算法虽然具有很多优点，但由于其是建立在某个复杂的单向函数的基础上，这就必然导致其加、解密速度远不能与私钥算法相提并论。因此，在实际的应用过程中，通常采用的方法是用私钥算法来传送密文，而用公钥算法来传送私钥算法的密钥，从而来保证安全性。 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。本论文将在实现它们的基础上，将用这两种算法来完成具有保密和鉴别能力的密钥交换。 本论文的第一章绪论介绍了国内外信息安全的有关动态和本论文的意义，第二章介绍信息安全的有关概念，第三章介绍密码学的有关知识，第四章对AES算法进行详细的分析、介绍，第五章对RSA算法进行分析、介绍，第六章介绍作者对RSA算法有关实现细节进行的改进，包括大数的存储、运算方法，平方乘算法的改进等等，最后一章介绍了几种密钥交换方法，并对其中的一种进行了实现。 本论文所介绍的算法虽然对RSA算法进行了某些局部改进，但还有许多不够完善的地方，有待于进一步提高。而所介绍的密钥交换要求通信双方事先知道对方的公开密钥，这就必然要与证书发放机构相联系才能保证最大的安全，这样就限制了其应用范围。因此，整个算法还存在很多有待于完善的地方。更多还原

【Abstract】 The modern society is a information society. With the rapid development of the Internet, the whole world was tied more and more tightly. This has brought human being society great convenience, at the same time, also brought a series of serious problems in which the information security is the most outstanding one. Because there are many sensitive and important data on the internet, the information security has been paid to more and more attention. To ensure the security of information, the general way is through building the regulations of information government and the methods of cryptology.Cryptology is the core of the information security. Modern cryptograph divides into the public key system and the private key system. The private key system is also called the single key system, its encryption process is the same as its decryption process. The public key system is also called the double key system, its encryption process is different with its decryption process. Because the public key system can publish its public key and only keep its private key secret , it has many new functions such as the digital signature and authentication, which is widely used in every area of the society.Though the public key algorithm has great advance, its running speed can not compare with the private key system for it is based on a complicated trapped function. In the actual application, the general way is to use the public-key algorithm transmitting the key of the private key system and the private key algorithm transmitting the cipher text. This way can ensure the security.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. This article will finish a secure and authenticable key exchange on the base of the two algorithms.The first chapter is the exordium. This article introduces some concepts concerning information security in the second chapter; introduces knowledge about cryptology in the third chapter; introduces the AES algorithm in the 4th chapter; the 5th chapter is the introduce and analysis to the RSA algorithm; the 6th chapter introduce the improvement of the RSA algorithm including the big_number restore and operation and the improvement algorithm of the "squaremultiply" algorithm. In the last chapter, the key exchange is introduced.Though this article makes much improvement to the RSA algorithm, there is still many no perfect place and need to improve later. The key exchange algorithms need connect with the CA institution because the communication sides need the public key each other, this confines the application of this algorithm. So there is a big room to improve for this article.更多还原