A Key-Policy Attribute-based Encryption Scheme for General Circuit from Bilinear Maps

By access structure and attribute set, attribute-based encryption realizes fine-grained access control and one to many encryption. The expression of access structure directly decides the application range of one scheme and the general circuit reaches the best form. Since the safety of multilinear maps is suffered question, using relatively efficient and safe bilinear maps to construct circuit attributebased encryption becomes popular. In this paper, we first propose a method that can convert any monotone circuit to an equivalent access tree. Then based on it, we propose a key-policy attribute-based encryption for general circuit from bilinear maps. Moreover, combining exiting method that can convert any access tree into LSSS structure and plenty of well-developed LSSS schemes, we can directly obtain corresponding circuit schemes. Compared with currently scheme from bilinear maps, our work is more efficient and expandable. In the standard model, selective security of our scheme is proved under the decisional bilinear Diffie-Hellman assumption.