A Study on Visual Multiple Secrets Sharing Schemes by Different Superimposition Positions

• Main Authors: Yi-Hao Li, 李翼豪
• Other Authors: Shyong Jian Shyu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/39071390944547175869

碩士 === 銘傳大學 === 資訊工程學系碩士班 === 102 === Visual cryptography proposed by Noar and Shamir in 1995, one secret image is encoded into several transparencies (shares), which reveal the secret to the human visual system when they are superimposed. Visual multiple secret sharing schemes are relatively new researchs, which decrypting shares with additional operation such as turning and/or flipping. In this paper, we propose novel visual multiple secret sharing schemes by superimposing shares at different distances. In our schemes, several secret images would be encoded into two shares with different share size, which reveal two secrets with two distant superimposition positions, and reveal five secrets with additional shift operations. The pixel expansion of our schemes are ms1=4 (ms2=16), ms1=1 (ms2=4), ms1=2 (ms2=8), or determined by a custom distance. The distant superimposition for decoding enhances the confidentiality of the proposed scheme and the flexibility of the visual cryptographic system.