可穿刺的基于属性的匹配加密方案

Puncturable Attribute-based Matchmaking Encryption Scheme

现有的密码加密方案无法在实现双向细粒度访问控制的同时保证接收者解密数据的真实性和过去加密消息的前向安全性.为了解决上述问题,本文提出一种可穿刺的基于属性的匹配加密方案,该方案采用基于属性的匹配加密技术来实现双向细粒度访问控制和保证数据的真实性,并与穿刺加密技术相结合,使得接收方可以自己更新其解密密钥以撤销选定消息、接收方或者某时间段的解密能力,从而保证对过去消息的前向安全性.在随机预言模型下证明了本方案不仅可以抵抗选择明文攻击,还可以实现在选择消息攻击下存在不可伪造性.将本方案与其他相关的密码方案在功能及计算和存储开销进行对比,表明只有本方案能够同时实现双向细粒度访问控制、数据真实性以及前向安全性,且计算效率和存储开销适中.

Existing cryptographic schemes cannot simultaneously realize the bilateral fine-grained access control policy, the authenticity of data, and forward security. To tackle these issues, this paper presents a novel primitive referred as puncturable attribute-based matchmaking encryption,which combines the attributed-based encryption technique and the matchmaking encryption method to achieve bilateral fine-grained access control as well as to ensure data authenticity. Besides, the puncturable encryption technology is incorporated into the proposed encryption to revoke decryption capability for selected messages, such that authorized recipients can repeatedly update their decryption keys to recover the currently encrypted messages. It is proved that the proposed encryption achieves the indistinguishability under chosen-plaintext attacks, and also realizes the existence unforgeability under chosen message attacks. Finally, the proposed encryption is compared with other related cryptographic primitives in the functional aspect of several desirable features such as fine-grained access control, bilateral policy-matching, forward security without the assistance of the third party, data authenticity, and signature verification. The results show that the proposed encryption can achieve all the above desirable properties, which makes it more appropriate for real-world applications. Besides,the elaborated performance comparisons are indicated to show that the proposed encryption achieves a good trade-off between the properties and the performance of computation and storage cost.