An Optimal Lower Bound on the Communication Complexity of Gap-Hamming-Distance

We prove an optimal (n) lower bound on the randomized communication complexity of the much-studied GAP-HAMMING-DISTANCE problem. As a consequence, we obtain essentially optimal multi-pass space lower bounds in the data stream model for a number of fundamental problems, including the estimation of frequency moments. The GAP-HAMMING-DISTANCE problem is a communication problem, wherein Alice and Bob receive n-bit strings x and y, respectively. They are promised that the Hamming distance between x and y is either at least n/2 + n or at most n/2 n, and their goal is to decide which of these is the case. Since the formal presentation of the problem by Indyk and Woodruff (FOCS, 2003), it had been conjectured that the na

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Amit Chakrabarti, Oded Regev
• Keywords: Communication, CORR 2010, Education, GAP-HAMMING-DISTANCE Problem, Gaussian Space