A lattice-based public key encryption scheme with delegated equality test

Abstract

When data security is facing growing threats, ordinary encryption techniques cannot meet the needs of comparing, sharing, and classifying data hidden in ciphertexts. At the same time, the advent of the quantum computing era has brought unprecedented challenges to traditional cryptography. Fortunately, a lattice-based PKEET scheme can solve the above problems. In this paper, we design a lattice-based PKE-DET scheme that can support the delegated tester function with satisfying anti-quantum computing security and resisting OMRA attacks. To the best of our knowledge, this is the first PKE-DET scheme that has both kinds of security at the same time. Under the standard model, we prove the security of the scheme based on the LWE hardness assumption. Compared with existing schemes, our scheme has many advantages, such as high security, delegated tester authorization, and small storage space.