Designs, Codes and Cryptography

, Volume 38, Issue 2, pp 219–236

Cheating in Visual Cryptography

Article

DOI: 10.1007/s10623-005-6342-0

Cite this article as:
Horng, G., Chen, T. & Tsai, D. Des Codes Crypt (2006) 38: 219. doi:10.1007/s10623-005-6342-0

Abstract

A secret sharing scheme allows a secret to be shared among a set of participants, P, such that only authorized subsets of P can recover the secret, but any unauthorized subset cannot recover the secret. In 1995, Naor and Shamir proposed a variant of secret sharing, called visual cryptography, where the shares given to participants are xeroxed onto transparencies. If X is an authorized subset of P, then the participants in X can visually recover the secret image by stacking their transparencies together without performing any computation. In this paper, we address the issue of cheating by dishonest participants, called cheaters, in visual cryptography. The experimental results demonstrate that cheating is possible when the cheaters form a coalition in order to deceive honest participants. We also propose two simple cheating prevention visual cryptographic schemes.

Keywords

visual cryptographycheatingsecret sharingvisual authentication

AMS Classification

94A62

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Department of Computer ScienceNational Chung Hsing UniversityTaichungR. O. C
  2. 2.Department of Information ManagementHsiuping Institute of TechnologyDali City,Taichung County 412Taiwan R. O. C.