A (k,n) Visual Cryptography Based on Shamir's Secret Sharing

This paper proposes a (k,n) visual cryptography based on Shamir's secret sharing (VCSSS). Using Shamir's secret sharing, a binary secret image can be shared into n meaningless shares, in order to make the generated shares more like noise images, adding the randomness within the process of sharing. Picking any k shares from n meaningless shares, the secret image can be revealed by using Lagrange interpolation. The main contribution of this paper is that applying Shamir's secret sharing to realize a (k,n) visual cryptography, and this method neither requires code book nor suffers from pixel expansion. Experimental results show VCSSS can realize a (k,n) visual cryptography, and correct decoding rate (CDR) of revealed secret image can be guaranteed.