Efficient visual cryptographic techniques for gray scale and colour images

Abstract

In the emerging internet technology transferring multimedia files has become newlineinevitable over cyberspace. It is extremely essential these days to provide data newlinesecurity, especially in the era of ever-increasing cyber-crimes across the world. newlineVisual Cryptography (VC) is an encrypting scheme through which image can be transmitted to the recipient with utmost confidentiality and secrecy. In Visual Cryptography, n prototypes called shares are formed by splitting the inputimage. The input image is rebuilt at the receiving end by assembling these prototypes together. Secret Sharing Schemes can be evaluated by the four newlineparameters: Storage Requirement, Computational Complexity, Reconstruction newlinePrecision, and Security. This research work is an effort to design new methodologies in VC techniques to achieve betterment in these objectives.Efficient Visual Cryptographic techniques for grayscale and color images are newlineproposed in this work to improve the security in transmission and to get better precision of the retrieved secret images. The VC techniques proposed are based on the randomization method and generation of shares with mathematical computations, a collaborative technique for multiple secret sharing. Randomized VC deals with share creation by randomly disintegrating the secret image that is very useful for military applications. Mathematical computation uses boolean techniques for creating the shares that leads to lossless recovery of the secret newlineimages. This is used effectively for applications where minute details of the newlineimages take precedence over bandwidth requirements such as in satellite images. VC with a share hiding technique is proposed to achieve better security. newlineThis technique is helpful in today s internet usage scenarios. Collaborative VC is proposed as an application of VC in the banking sector. Collaborative VC enriches the application scenarios wherein the same participant in different groups can use a single key as a share for retrieving more than one secret image. newline