高效撤销的密文策略属性基加密方案

摘要：作为新型的密码学原语，属性基加密方案通过一系列属性来定义一个用户，并且实现了细粒度访问控制。然而，复杂、耗时的撤销操作成为限制属性基加密方案应用的瓶颈问题。为了解决属性基加密方案中的撤销问题，本文提出一种高效属性撤销的密文策略属性基加密方案。该方案通过固定长度的撤销列表记录撤销用户，撤销过程不必更新系统密钥及相关用户的密钥，大大降低了撤销所引起的计算开销。

CP ABE Scheme with Efficient Attribute Revocation

As a new cryptographic primitive, attribute based encryption (ABE) scheme uses several attributes to identify a user and achieves fine grained access control. However, the complex issue of user revocation has become a bottlenect in ABE schemes. To solve the problem, the paper proposed a ciphertext policy attribute based encryption (CP ABE) scheme with efficient user revocation. In this scheme, lists with content length are maintained to record the revoked users. Attribute revocation was excuted by the trusted authority without updating the keys of the system and the associated users, which reveals computation overhead in revocation.: