可撤销的广义身份基密码算法研究

发布时间：2018-05-25 18:13

本文选题：用户/属性撤销 + 密钥泄漏　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：随着互联网技术的迅速发展和云计算的普及,数量众多的敏感数据借助网络进行交换并通过云服务器进行存储。网络丰富、方便了人们的生活,但其本身也存在着许多安全问题需要解决,因而必须对网络的安全性提出更高的要求。当许多密码方案直接应用在用户生活中与利益相关的多种场景时,用户密钥泄漏、过期或者属性发生变更往往是不可避免的。因此,在公钥密码系统中,特别是基于身份的密码体制与基于属性的密码体制中,研究如何及时有效撤销用户和属性意义重大。本文研究身份基签密方案和属性基加密方案中的可撤销技术。主要成果有以下两个方面:1.研究总结了现有各种身份基签密方案及其存在的撤销问题,并提出了一种可撤销的基于身份的签密方案。在新方案中,不仅可以实现用户撤销与密钥更新,同时也可以达到任何第三方对密文进行公开可验证性要求。在标准模型下,证明了所提方案基于DBDH困难问题假设,具有适应性选择密文攻击不可区分性;基于CDH困难问题假设,具有适应性选择消息攻击不可伪造性,保证了方案在实际应用中的安全性。2.研究总结了现有各种属性基加密方案及其存在的撤销用户和属性等方面的问题,并提出了一种可以高效、及时撤销用户属性的密文策略属性基加密方案。新方案达到了细粒度的访问控制,不仅可以实现用户级的撤销,而且达到了属性级的撤销。另外,在标准模型下,证明了所提方案基于DPBDHE困难问题假设是安全的,同时方案还具有机密性,抗共谋攻击性,前向、后向安全性。
[Abstract]:With the rapid development of Internet technology and the popularity of cloud computing, a large number of sensitive data are exchanged through the network and stored through cloud servers. The network is rich and convenient for people to live, but there are many security problems to be solved, so it is necessary to put forward higher requirements for the security of the network. When many cryptographic schemes are directly applied to a variety of scenarios related to the interests of the user, it is inevitable that the user key leaks, expires or the properties change. Therefore, in public key cryptosystem, especially in identity-based cryptosystem and attribute-based cryptosystem, it is of great significance to study how to cancel users and attributes in time and effectively. In this paper, we study the revocation techniques in identity-based signcryption schemes and attribute-based encryption schemes. The main achievements are as follows: 1. In this paper, we summarize the existing identity-based signcryption schemes and their existing revocation problems, and propose a revocable identity-based signcryption scheme. In the new scheme, not only the user revocation and key update can be realized, but also the requirement of any third party to publicly verify the ciphertext can be achieved. Under the standard model, it is proved that the proposed scheme is indistinguishable from the adaptive selection ciphertext attack based on the DBDH difficult problem hypothesis, and the adaptive selection message attack is unforgeable based on the CDH difficult problem hypothesis. It ensures the security of the scheme in practical application. This paper studies and summarizes various kinds of attribute-based encryption schemes and their existing problems such as revocation of users and attributes, and proposes a ciphertext policy attribute-base encryption scheme, which can efficiently and timely revoke the attributes of users. The new scheme achieves fine-grained access control, which can not only achieve user-level revocation, but also achieve attribute-level revocation. In addition, under the standard model, it is proved that the proposed scheme is safe based on the DPBDHE difficult problem assumption, and the scheme is also confidential, anti-collusion, forward and backward security.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN918.4

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