可容錯的多重視覺機密分享機制之研究

A Study on the Fault-Tolerant Visual Multi-Secrets Sharing Schemes

林仁昱(Jen-Yu Lin)

指導教授 ： 阮夙姿

國立暨南國際大學/科技學院/資訊工程學系/碩士(2017年)

摘要

視覺機密分享(Visual Secret Sharing, VSS)是一種影像加密技術，他將機密影像加密成兩張無意義的分享影像(share)，使其在解密時不需要透過任何的計算，只單單用人類的肉眼(Human eye)就可以直接還原出隱藏影像內的資訊。
隨機網格(Random Grid)是一個簡單且低成本的技術，它的優點是不需建置密碼本(Code Book)，並且其產生出來的分享影像與原來的機密影像大小一樣。但在實際應用中，精準的對齊每一個像素是非常困難的，我們希望在稍許的誤差下依然可以辨識出隱藏的秘密。因此本研究提出了在不擴張像素的條件下，同時加密多張機密影像後得到兩張分享影像，使其在疊合分享影像時利用平移其中一張分享影像來還原多張機密影像，並且使其達到不完全對齊時仍可辨識出機密影像內資訊的目的，如此將可使視覺機密配置系統更具實用性。

關鍵字

視覺機密分享 ； 機密分享 ； 隨機網格 ； 容錯 ； 像素擴張

並列摘要

Visual cryptography is to encrypt a secret image into two meaningless random images, called shares, such that it can be decrypted by stacking these two shares without any calculations. Random grid is a simple and low-cost method, the main research for encrypting many secret images into two shares are proposed. The size of each share will be the same size as the secret image. In practice, there would be problems in alignment when staking these two shares by hand. Besides, share more secret images in the same time will enhance the functionality of the scheme. Therefore, this study propose a new visual secret sharing scheme which encrypt
multi-secret images into two shares in the same time, and it is not necessary to align the shares precisely from image encryption without pixel expansion. Both theoretical analysis and simulation results demonstrate the e ffectiveness and practicality of the proposed scheme.

並列關鍵字

Visual cryptography ； visual secret sharing ； random grid ； tolerance ； pixel expansion.

參考文獻

[1] J. J.Y. Chang. Visual Multi-Secret Image Sharing Schemes by Shifting Random

Grids. Master Thesis of Department of Computer Science and Information

Engineering National Chi Nan University, 2012.

[2] J. J.Y. Chang and J. S.T Juan. Multi-vss scheme by shifting random grids. In

Proc. World Academy of Science, Engineering and Technology, (65):1277 1283,