A Study on Novel Visual Secret Sharing Schemes

• Main Authors: Jen-Bang Feng, 馮振邦
• Other Authors: Yen-Ping Chu
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/93861671205421327527

博士 === 國立中興大學 === 資訊科學與工程學系 === 96 === Visual cryptography is a rising sub-field in the research of secret sharing. Except the properties of secret sharing, the decryption does not need any computation that the secret image reveals in human vision by just stacking the shares together. Therefore, visual cryptography is capable for emergency and special situations. However, there are plenty of rooms for improving in visual cryptography. For example, share images of current visual secret sharing schemes look like noise. It would be easy to hide the share images if the shares look like natural pictures. Also, different participants can only decrypt the same secret, and only one secret image can be decrypted from the participants. Therefore, we develop a new visual secret sharing scheme based on pixel swapping to generate two meaningful share images that the stacking results are better than existing schemes. In addition, the proposed scheme can cooperate with other schemes to enhance the quality. Then a new generalized visual secret sharing scheme is developed in this dissertation that different combination of shares can decrypt different secret images. Finally, a new idea to share multiple secret images in two share images is designed. Currently, the number of secrets is limited by two for two share images. According to the proposed relationship, the number is extended to general in our scheme with reasonable expanding ratio. The proposed schemes in this dissertation extend the research of visual cryptography and may be applied to more applications.