Symmetrically Oblivious Envelope Protocol

This paper considers the privacy issues in attribute-based access control systems, and presents a privacy-preserving access control protocol named as symmetrically oblivious envelope protocol. Its important property is symmetric privacy, i.e., the resource owner can´t learn attribute values of the resource requester, and the resource requester can´t learn access control policies established by resource owner. The proposed protocol can support access control policies constructed by various comparison predicates such as =, >, ges, <, les, as well as logical combinations of them. The security of the protocol is proved under the discrete logarithms assumption and computational Diffie-Hellman assumption.