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.