Research & Publication

Abstract:Visual cryptography (VC) is a paradigm of cryptography which prevents a secret from being modified or destructed by using the notions of perfect cipher and the secret can be reconstructed by the human visual system. It is a cryptographic technique which can encrypt visual information, such as images and text; and can decrypt the secret without a computer (stack operation). This visual secret sharing scheme is developed by Moni Naor and Adi Shamir in 1994. Most of the visual cryptography schemes suffer from many drawbacks such as: pixel expansion, share management difficulty, poor quality recovered image etc. So this paper discusses a visual cryptography scheme using random grids, where it uses a common share to transmit ‘n’ binary secret. The binary secret image is divided into two share images (random grids) as in (2, 2) visual cryptography scheme. Here it uses ‘n+1’ share images to transmit ‘n’ secrets and the extra share is common to all ‘n’ secrets. Since RG is used it creates shares without pixel expansion. This scheme can be viewed as a modified scheme of (2, 2) random grid based visual cryptography. One share is considered as a common share to all n secrets, so it makes efficient network bandwidth utilization.