A Weighted Threshold Visual Cryptography

  • Tai-Yuan Tu
  • Tzung-Her Chen
  • Ji-min Yang
  • Chih-Hung WangEmail author
Conference paper
Part of the Communications in Computer and Information Science book series (CCIS, volume 1013)


Over the past years, a visual secret sharing scheme gave each share the same ability to reconstruct the secret image. That means each participant had the same significance to reveal the secret. However, it is not realistic in real world for some applications. In this paper, the weighted \( (k,n) \)-threshold visual cryptography scheme is proposed, in which the secret image is encoded into some shares with different weights and the sum of weights for all shares has to be equal to \( n \), according to the share-holders of different priority levels. In the decoding phase, when the shares with different weights are superimposed and the sum of weights of all stacking shares is equal to or larger than \( k \), the secret is then visually recognizable. Otherwise, no information about secret image is revealed. The proposed scheme is the first weighted \( (k,n) \)-threshold visual cryptography method with no pixel expansion. It is suitable for applications in the real life.


Cryptography Visual cryptography Weighted visual secret sharing Probabilistic visual secret sharing 



This research was partially supported by Ministry of Science Technology, Taiwan, R.O.C., under contract no. MOST 105-2221-E-415 -012.


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Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Tai-Yuan Tu
    • 1
  • Tzung-Her Chen
    • 1
  • Ji-min Yang
    • 1
  • Chih-Hung Wang
    • 1
    Email author
  1. 1.Department of Computer Science and Information EngineeringNational Chiayi UniversityChiayiTaiwan

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