Visual cryptography is a perfectly secure way to protect secrets and is characterized by its decryption method. This project is to develop new visual cryptographic scheme satisfying certain conditions. In this project, a secret image is split into a set of shares, so that some authorized shares can have access to the secret, where as other unauthorized shares cannot leak out any secret information. To recover the secret image, one has to collect a set of qualified shares and print them on to transparencies. As long as all the transparencies are stacked up, the secret image will reveal on the stacked image. Since the secret image can be identified with human eyes without any complex decryption algorithms or the aid of computers, visual cryptography schemes can be very suitable for the situation when computers are not available.
The project proposes to develop new algorithms, and algorithms based on paradigm of the existing secure algorithms, for secure symmetric encryption schemes and associated secure key management protocols. The strength of the proposed algorithms are tested and established through standard tests and cipher specific crypt analysis.