Identity-based matchmaking encryption without random oracles

Identity-based matchmaking encryption (IB-ME) is a generalization of identity-based encryption where the sender and the receiver can both specify a target identity: If both the chosen target identities match the one of the other party, the plaintext is revealed, and otherwise the sender’s identity, the target identity, and the plaintext remain hidden. Previous work showed how to construct IB-ME in the random oracle model. We give the first construction in the plain model, based on standard assumptions over bilinear groups.