Efficient Inner Product Encryption With Simulation-Based Security

An inner product encryption (IPE) scheme is a special type of functional encryption where the decryption algorithm, given a cipher-text related to a vector x and a secret key to a vector y, computes the inner product < x,y >. A function-hiding IPE scheme requires that the secret key reveals no unnecessary information on the vector y besides the privacy of the vector x. In this paper, we construct a function-hiding IPE scheme using the asymmetric bilinear pairing group setting of prime order. Compared with the existing similar schemes, our construction both reduces necessary storage complexity and computational complexity by a factor 2 or more and achieves simulation-based security, which is much stronger than indistinguishability-based security, under the External Decisional Linear assumption in the standard model.