WEB-VC: VISUAL CRYPTOGRAPHY FOR WEB IMAGE

Abstract

y The conventional encryption techniques of visual cryptography are extended to web page. The key point is that Cascading Style Sheet blend modes can simulate stacking operators. The multiply blend mode can be regarded as Boolean OR operator, and the difference blend mode can be regarded as exclusive-OR (XOR) operator. Thus, the secrets can be revealed in a web browser by overlapping shares together without any additional computation. We named this scheme Web-VC. The decoding procedure of Web-VC is just like usual visual cryptography, while digital shares can be used in this case. Web-VC has strong ability of resisting compression and transcoding without losing the secret. Another contribution of this work is the method of XOR-based flip visual cryptography.