XOR-based unexpanded meaningful visual secret sharing scheme

Visual cryptography is a technique to conceal the secret information into n shares, distributed to n participants. When any k ≤ n, 2 ≤ k ≤ n, shares are printed on transparencies and stacked together, information about secret image can be revealed directly by the human visual system with poor visual quality. It is an issue for the researchers, to improve the quality of shares and reconstructed image. This paper proposes n-out-of-n, n = 2 × i, i = 1, 2, 3 XOR-based unexpanded meaningful visual secret sharing scheme for binary or halftone secret image. When all the shares are 'XOR'ed, it reveal secret image without any loss. Feasibility of the proposed scheme is checked by extensive experimental results on a binary image. Experimental results and comparison with related works show that proposed scheme performs better than the state-of-the-art approaches. It is analysed on the basis of some quality metrics to evaluate the performance.