An Overview of Visual Cryptography using Random Grids

Security has become an important issue in the world now. Visual cryptography (VC) is a technique which provides information security which uses simple stacking operation instead of complex, computationally intensive algorithms used in traditional cryptography. This technique allows image to be encrypted in such a way that their decryption can be performed by the human visual system. This technique encrypts a secret image into transparencies such that stacking a sufficient number of transparencies reveals the secret image. However, several VC methods have the problem of size expansion. VC using random grids is a solution for generating non-expansible transparencies. In this paper, an overview of the Visual Cryptography (VC) using random grids is introduced.