The Revocable Attribute Based Encryption Scheme for Social Networks

Attribute based encryption is one of the candidates to secure online social network. Providing an efficient revocation mechanism in attribute based encryption scheme is very important. To achieve the hierarchical access control and improve update efficiency, the revocable attribute based encryption scheme with hierarchical revocation based on multilinear maps is proposed. The shared file is divided into three portions. The user with the specific attributes will access the corresponding portion. The analysis shows that it has the constant key size and has the indistinguishability under chosen plaintext attacks.