Eur. Phys. J. D (2012) 66: 110
https://doi.org/10.1140/epjd/e2012-30065-9

Regular Article

Information leak in Liu et al.’s quantum private comparison and a new protocol

¹ State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
² State Key Laboratory of Integrated Services Network, Xidian University, Xi’an 710071, P.R. China
³ Beijing Electronic Science and Technology Institute, Beijing 100070, P.R. China

^a e-mail: liyanbing1981@gmail.com

Received: 26 January 2012
Published online: 30 April 2012

Abstract

In a recent paper [W. Liu, Y.B. Wang, Z.T. Jiang, Opt. Commun. 284, 3160 (2011)], a quantum private comparison (QPC) protocol based on W states was presented. Compared to the previous QPCs, the protocol is promising for that it can prevent the comparison result from revealing to the third party. However, this study point out that a flaw of information leak is existent in the protocol. And a new QPC which can avoid the flaw and has higher efficiency is proposed in this paper.