Amortized communication complexity of an equality predicate

Abstract

We study the communication complexity of the direct sum of independent copies of the equality predicate. We prove that the probabilistic communication complexity of this problem is equal to O(N); the computational complexity of the proposed protocol is polynomial in the size of inputs. Our protocol improves the result achieved in 1991 by Feder et al. Our construction is based on two techniques: Nisan's pseudorandom generator (1992, Nisan) and Smith's string synchronization algorithm (2007, Smith). © 2013 Springer-Verlag Berlin Heidelberg.