The Comparative Study on Visual Cryptography and Random Grid Cryptography

Visual cryptography scheme is a cryptographic technique which allows visual information to be encrypted into several shares in such a way that the decryption can be performed by the human visual system, without the aid of computers. Random grid is a methodology to construct visual secret sharing (vss) scheme without pixel expansion in which an RG scheme takes an input image and transforms it into multiple cipher- grids that provide no information on the original image and the resulting decrypted image retains the size of the original image. Intent of this paper is on comparative study of visual cryptography and Random grid cryptography on the basis of analysis and correctness of simple VC schemes and RG schemes, i mproving contrast of the reconstructed image using various algorithms and multiple-image encryption using rotating angles. Keywords - ideal contrast, random grid scheme, ring shadow technology, rotating random grids, visual cryptography scheme.