Secure-channel free searchable encryption with multiple keywords: A generic construction, an instantiation, and its implementation

In public key encryption with keyword search (PEKS), a secure channel is required in order to send trapdoors to the server, whereas in secure-channel free PEKS (SCF-PEKS), no such secure channel is required. In this paper, we propose a generic construction of SCF-PEKS with multiple keywords (SCF-MPEKS) from hidden vector encryption, tag-based encryption, and a one-time signature. Our generic construction provides adaptive security, where the test queries are allowed in the security model, and does not require random oracles. In addition to providing an instantiation of our generic construction, which is the first adaptive secure SCF-MPEKS scheme in the standard model, we implement the SCF-MPEKS scheme by using the PBC library. Moreover, we extend the Boneh-Waters range search technique, and show that the running time of our encryption algorithm is approximately twice as fast as that of the Boneh-Waters encryption algorithm.