On generating meaningful shares in visual secret sharing scheme

Abstract

In the k-out-of-n visual secret sharing scheme (VSSS) proposed by Naor and Shamir, a binary secret image is encoded into n shares called transparencies. Each share, consisting of black and white pixels, is in the form of noise and has size larger than that of the secret image. The binary secret image can be decoded by using the visual system through superimposing any k of n transparencies without performing any cryptographic computation. In practice, meaningless shares, however, might invite the adversary's attention and to manage numerous increasing transparencies belonging to different secrets is also a problem. In the present paper, a simple method to transform meaningless shares in VSSS into natural colourful images is proposed. Experiment results show that this method does provide a general solution to the k-out-of-n VSSS with few additional pixel expansions and low computational power as compared with others.

Keywords:

• SECRET SHARING
• VISUAL SECRET SHARING
• MEANINGFUL SHARES