Improving Contrast in Random Grids Based Visual Secret Sharing
Sachin Kumar, R. K. Sharma · 2012
In the existing random grids based (n, n) visual secret sharing (VSS) schemes, decryption is done with the help of human visual system by stacking the cipher grids. The stacking operation is computationally modeled as Boolean OR operation, which suffers from two drawbacks. Firstly, the contrast of the reconstructed image decreases exponentially by increasing n (≥2) and secondly, it requires perfect alignment of stacking the cipher grids. In this paper, we propose Boolean XOR operation as decryption operation for the existing random grids based (n, n) VSS schemes. The proposed operation removes both the drawbacks and does lossless secret reconstruction. We have demonstrated the improvement in the contrast of the reconstructed image by formal proofs and experimental results.