期刊名称：International Journal of Computer Science and Information Technologies
电子版ISSN：0975-9646
出版年度：2014
卷号：5
期号：3
页码：3985-3990
出版社：TechScience Publications
摘要：Security of information hiding become important in a number of application areas of today’s world. Audio, video, pictures are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice or several number or even help to prevent unauthorized copying directly. Visual Cryptography Scheme (VCS) is a cryptographic technique in which visual information(e.g. printed text, pictures etc.) encrypted by generating shares (transparencies) of a binary secret image into meaningless shadow images, where decryption can be performed by a human visual system without any computational cost. There are various measures on which performance of VCS depends, such as pixel expansion, contrast, security, computational complexity, meaning full or meaningless share generation, types of secret images (either binary or color ) and the number of secret images encrypted by the schemes. Some research is going on in VCS with no expansion of share size compared with original secret image. In this survey paper we try to summarize size invariant share generation techniques in VCS.
