Oblivious transfer with access control

Ref: Jan Camenisch, Maria Dubovitskaya and Gregory Neven. In E. Al-Shaer, S. Jha, and A. Keromytis, editors, Proceedings of the 2009 ACM Conference on Computer and Communications Security, pages 131-140. ACM Press, 2009.

Abstract: We present a protocol for anonymous access to a database where the different records have different access control permissions. These permissions could be attributes, roles, or rights that the user needs to have in order to access the record. Our protocol offers maximal security guarantees for both the database and the user, namely (1) only authorized users can access the record; (2) the database provider does not learn which record the user accesses; and (3) the database provider does not learn which attributes or roles the user has when she accesses the database. We prove our protocol secure in the standard model (i.e., without random oracles) under the bilinear Diffie-Hellman exponent and the strong Diffie-Hellman assumptions.