机构可问责的可追踪属性基加密方案

Traceable Attribute-based Encryption Scheme with Accountable Authority

在属性基加密中,多个用户会共享公共属性,其中的一些用户可能会恶意地泄漏解密密钥,被追踪到的用户可能认为是管理机构泄漏密钥。为此,给出一个新的可追踪属性基加密方案,当被追踪到的用户质疑结构的可信性时,可运行问责算法确认是机构或用户的恶意行为。方案中的属性管理机构和身份管理机构均不能独立地解开系统中的密文。分析结果表明,该方案不仅实现用户的可追踪性,而且解决了可追踪密文策略属性基加密的机构可信依赖问题,实现了对管理机构的可问责性。

In Attribute-based Encryption（ABE）, as the users in an ABE system may share some common attributes, some malicious users may leak their decryption ability corresponding to the common attributes. As the authority of ABE system can use the master secret key to generate any secret keys, a traced user may argue that it is the authority that generates the leaked secret key. This paper presents a scheme of an accountable and traceable ABE of an authority. A traced user can take advantage of accountability algorithm to further check whether it is the malicious act from the authority or the user. In this scheme, the authority of ABE system and the authority of identity management are mutually independent,and cannot unlock the ciphertext by their own. Analysis shows that the scheme not only realizes the user traceable, but also solves the credit problem of the authority of ABE system with accountability.