CCA-Secure Attribute-Based Encryption Supporting Dynamic Membership in the Standard Model

Attribute-based encryption (ABE) is an access control mechanism where a sender encrypts messages according to an attribute set for multiple receivers. With fine-grained access control, it has been widely applied to cloud storage and file sharing systems. In such a mechanism, it is a challenge to achieve the revocation efficiently on a specific user since different users may share common attributes. Thus, dynamic membership is a critical issue to discuss. On the other hand, most works on LSSS-based ABE do not address the situation about threshold on the access structure, and it lowers the diversity of access policies. This manuscript presents an efficient attribute-based encryption scheme with dynamic membership by using LSSS. The proposed scheme can implement threshold gates in the access structure. Furthermore, it is the first ABE supporting complete dynamic membership that achieves the CCA security in the standard model, i.e. without the assumption of random oracles.