A simple visual secret sharing scheme employing particle swarm optimization

Encryption of digital image is a thrust research area worldwide. Visual cryptography is a simple and efficient technique to encrypt digital image without any hard computation. The technique encrypts a secret image into a number of shares and secret image cannot be revealed from any individual share. The secret image can be decoded using human visual system by stacking all the shares. Previous research works are almost restricted to binary images by expanding the pixels. In this paper, a new visual cryptography scheme for grayscale image employing particle swarm optimization (PSO) is proposed. Here shares are generated gradually though a number of iterations from the input secret image by comparing the image with resultant image. The results obtained from the proposed scheme show the strength of the stochastic optimization algorithm in the field of visual cryptography.