Efficient and secure equality tests

Secure equality testing of two private values is one of the fundamental building blocks of many cryptographic protocols designed for Signal Processing in the Encrypted Domain (SPED). Existing protocols introduce significant amount of computation and computational overhead, which makes it essential to search for new and novel, efficient equality tests for the design of SPED algorithms. In this paper, we first describe the state-of-The-Art equality tests, and then propose two cryptographic protocols which are significantly more efficient than the existing work. Our proposals achieve high performance due to algorithmic changes and successful deployment of data packing. Furthermore, we also present a novel secure exponentiation protocol as a part of our first equality test. Complexity and performance analyses clearly indicate the high efficiency of our protocols in terms of computation cost.