漸進式圖像秘密共享在去識別化和訪問控制中的應用

Progressive Image Secret Sharing in De-Identification and Access Control

吳雨澄(Daniel Wu)

指導教授 ： 吳家麟

國立臺灣大學/電機資訊學院/資訊工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201801318

摘要

去識別化是近幾年很重要的議題。而秘密共享則是一種密碼學上的方法讓我們可以安全地將秘密分享出去，任何人只要有 k 個秘密則他可以正確的解碼原始的秘密。我們將這兩個想法結合在一起，提出一個能應用在監視器、醫療紀錄以及資料管理上這種需要保護隱私的環境裡的漸進式秘密共享方法。
在這篇論文中，我們根據修改過的 Shamir 秘密分享方法以及 Hung 提出的漸進式影像分享方法，提出了一個漸進式的圖像秘密共享演算法。在我們的方法中，我們可以將一個圖像依照指定的隱私區域與要求的閥值做漸進式秘密分享，而我們只要管理能接觸到的分享份數就可以很輕易地做到存取控制。我們的方法所使用的金鑰是圖片大小、第幾份分享、以及（或）閥值的分佈情況。我們不需要任何額外的資訊如隱私區域的位置或大小，因此提高了安全性。在實驗結果中我們展示了高品質的多級別存取控制結果。

關鍵字

漸進式秘密共享 ； 圖像秘密共享 ； 存取控制 ； 去識別化 ； 隱私保護

並列摘要

De-Identification is an important issue that are getting more attention recently. Secret Sharing is a type of cryptographic method used to securely distribute digital media such as images, and with k or more shares, the secret media can be fully reconstructed. We combined these two idea, and proposed a progressive secret sharing method that can be used on privacy-concerned situation, such as security camera, medical records, or data management.
In this thesis, we proposed a progressive image secret sharing method, which is based on the modified Shamir’s secret sharing scheme, and the idea of Hung’s progressive image sharing scheme. In our approach, we can share the image based on the assigned sensitive area and chosen threshold, so that we can do the access control by the share number. The key of our sharing scheme depends on the image size, share number, and/or the distribution of the threshold. We don’t need the information of sensitive area, which enhanced our security. Experiment results shows the ability of our method in multi-level access control on both normal parts and sensitive parts with high visual quality.

並列關鍵字

Progressive Secret Sharing ； Image Secret Sharing ； Access Control ； De-Identification ； Privacy Preserving

參考文獻

[1] Shamir, A. (1979). How to share a secret. Communications of the ACM, 22(11), 612-613.

[2] Thien, C. C., & Lin, J. C. (2002). Secret image sharing. Computers & Graphics, 26(5), 765-770.

[3] Hung, K. H. (2003). Progressive image sharing (Doctoral dissertation, MS thesis, Department of Computer and Information Science, National Chiao Tung University, Taiwan).

[4] Ross, A., & Othman, A. (2011). Visual cryptography for biometric privacy. IEEE transactions on information forensics and security, 6(1), 70-81.

[5] Hung, K. H., Chang, J. J., & Lin, J. C. (2008). Progressive sharing of an image. Optical Engineering, 47(4), 047006.