公钥可验证的无证书公钥密码体制

发布时间：2018-01-09 19:20

本文关键词：公钥可验证的无证书公钥密码体制　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：1976年,Diffie和Hellman首次提出公钥密码体制的概念。可以说公钥密码体制是密码学史上最具有革命性的成果。但公钥密码体制中存在公钥认证的问题。在公钥基础设施中,公钥认证的问题是通过数字证书来解决的。虽然证书能够进行公钥认证,但证书也带来了诸如证书如何发送,证书的存储和证书到期时的废止或吊销等管理问题。为了解决证书管理问题,Shamir提出了一种新的密码体制—基于身份的公钥密码体制。在该体制中,用户的公钥是通过其独有的身份信息导出的,因此无需认证。但用户的私钥则是由秘钥生成中心产生的,也就存在秘钥托管问题。为了解决证书管理问题和密钥托管问题,Al-Riyami和Paterson提出了一种无证书公钥加密方案,并且在随机预言模型下证明了该方案是IND-CCA安全的。很长一段时间,大量的无证书公钥加密方案相继而出,但是其中很多方案的安全性都存在问题。于是提出一种高效并且可证安全的无证书公钥加密方案成为密码学者关注的焦点。本文对无证书公钥加密展开了进一步的研究和探讨,取得如下的研究成果:1 Baek,Safavi-Naini和Susilo提出的是一个不使用双线性对的无证书公钥密码体制。在证明该CLPKE方案在第一类攻击者的攻击下是IND-CCA安全的过程中,出现了一些理论性的错误,并且在整个安全性证明过程中并没有给出在第二类攻击者攻击下的安全性证明。本文首先指出并解决了安全性证明过程中出现的问题,之后补充证明了该CLPKE方案对于第二类攻击者在随机预言模型下也是IND-CCA安全的。2 Al-Riyami和Paterson给出的是一个基于双线性对的无证书公钥密码体制,但双线性对运算需要大量的计算花费。本文利用Schnorr签名给出了一个不使用双线性运算的无证书公钥加密方案。方案的公钥只须发送方即可验证。根据Girault对第三方信任机构TTP定义的信任等级,该方案达到了与公钥基础设施PKI中方案相同的等级—第三级。此外,在CDH问题是难解的前提下,证明了方案在随机预言模型下是IND-CCA安全的。
[Abstract]:1976. Diffie and Hellman put forward the concept of public key cryptosystem for the first time. It can be said that public key cryptosystem is the most revolutionary achievement in the history of cryptography. But there exists the problem of public key authentication in public key cryptosystem. In the public key infrastructure. The problem of public key authentication is solved by digital certificate. Although the certificate can authenticate public key, it also brings some problems such as how to send the certificate. In order to solve the problem of certificate management, a new cryptosystem named identity-based public key cryptosystem is proposed. The public key of the user is exported through its unique identity information, so no authentication is required, but the private key of the user is generated by the secret key generation center. In order to solve the problem of certificate management and key escrow, Al-Riyami and Paterson proposed a non-certificate public key encryption scheme. It is proved that the scheme is IND-CCA secure under the stochastic prediction model. For a long time, a large number of certificateless public key encryption schemes have emerged. However, many of the schemes have security problems. Therefore, an efficient and verifiable public key encryption scheme without certificates becomes the focus of attention of cryptographers. In this paper, the public key encryption without certificates is further discussed. In this paper. The following research results are obtained: 1 Baek. Safavi-Naini and Susilo propose a certificateless public key cryptosystem without bilinear pairings. It is proved that the CLPKE scheme is IND-. CCA security in the process. There have been some theoretical errors. And in the whole process of security proof, there is no security proof under the attack of the second type of attackers. Firstly, this paper points out and solves the problems in the process of security proof. Then it is proved that the CLPKE scheme is also IND-CCA secure for the second class of attackers under the stochastic prediction model. 2. Al-Riyami and Paterson give a certificate free public key cryptosystem based on bilinear pairings. However, bilinear pairings require a lot of computation cost. In this paper, a certificateless public key encryption scheme without bilinear operation is presented by using Schnorr signature. The public key of the scheme can be verified only by the sender. According to the level of trust defined by Girault to the third-party trust authority TTP. The scheme reaches the same level as the public key infrastructure (PKI) scheme-the third level. In addition, the CDH problem is difficult to solve. It is proved that the scheme is IND-CCA safe under stochastic prediction model.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN918.4

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