A New Resources Saving Scheme on Visual Cryptography

• Main Authors: Chun-Feng Chen, 陳群峰
• Other Authors: Shih-Hsiung Twu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/32625458453389794622

碩士 === 中原大學 === 電機工程研究所 === 97 === In this thesis, we propose an effective resource saving scheme on visual cryptography. Unlike traditional cryptography, visual secret sharing technology decodes a cipher text by using human’s eyes. It’s an excellent solution under the situation of not being able to decrypt by computer. Our proposed scheme is a brand new type of visual cryptography based on using pixel expansion method and changing turn angle method. For any two given square secret images, we use pixel expansion method to produce two corresponding transparencies S1 and S2. Both transparencies look noisy. When we stack the front views of both transparencies, the first secret image is obtained. Then we turn right ninety-degree on S2 and stack both transparencies again, the second secret image is obtained. In our proposed scheme, we also improve the noisy extent of share images. The contributions of our research are as follows: 1. In traditional visual cryptography, two share images can only be hidden one secret image. But in our proposed scheme, we can hide two secret images with two share images. 2. In traditional visual cryptography, hiding two secret images needs at least three share images, but we need only two share images on our proposed scheme. We can reduce amount of transparencies and black toner to reach to Energy Saving and Carbon Reduction purpose. We believe this study results will be probably practical and efficient to establish a useful visual cryptography scheme with above advantages in applications.