A Low Communication Competitive Interactive Proof System for Promised Quadratic Residuosity

  • Authors:
  • Toshiya Itoh;Masafumi Hoshi;Shigeo Tsujii

  • Affiliations:
  • -;-;-

  • Venue:
  • CRYPTO '93 Proceedings of the 13th Annual International Cryptology Conference on Advances in Cryptology
  • Year:
  • 1993

Quantified Score

Hi-index 0.00

Visualization

Abstract

A notion of "competitive" interactive proof systems is defined by Bellare and Goldwasser as a natural extension of a problem whether computing a witness w of x 驴 L is harder than deciding x 驴 L for a language L 驴 NP. It is widely believed that quadratic residuosity (QR) does not have a competitive interactive proof system. Bellare and Goldwasser however introduced a notion of "representative" of ZN* and showed that there exists a competitive interactive proof system for promised QR, i.e., the moduli N is guaranteed to be the product of k = O(log log |N|) distinct odd primes. In this paper, we consider how to reduce the communication complexity of a competitive interactive proof system for promised QR and how to relax the constraint on k from O(log log|N|) to O(log |N|). To do this, we introduce a notion of "dominant" of ZN* and show that promised QR with the constraint that k = O(log |N|) has a competitive interactive proof system with considerably low communication complexity.