Improved Extended Progressive Visual Cryptography Scheme Using Pixel Harmonization

Abstract

Security of information is of much concern in the modern internet era. Secret sharing schemes provide mechanism of encrypting secret information to prevent illicit usage. Visual cryptography is a secret sharing technique that facilitates encryption of a secret image. Visual cryptography allows us to effectively and efficiently share secrets among a number of trusted parties by hiding secrets within images. These images are encoded into multiple shares as per the rules indicated in basis matrices and later decoded by stacking required number of shares. Progressive visual cryptography has a specialty of recovering secret image as soon as more than one shares received gradually. Existing progressive visual cryptography schemes have severe limitations like data disclose on shares and higher pixel expansion. Improved progressive visual cryptography scheme deals with these limitations. Improved extended progressive visual cryptography scheme solves the issue of management of noise like meaningless shares by creating meaningful shares without any pixel expansion efficiently.