翻轉平移型視覺加密及多項式型分享的結合

An image sharing method combining flip-translated visual cryptography and polynomial-style sharing approaches

吳佳樺(Chia-Hua Wu)

指導教授 ： 林志青

國立交通大學/資訊學院/多媒體工程研究所/碩士(2014年)

https://doi.org/10.6842/NCTU.2014.00469

摘要

首先，我們提出三種視覺加密的方法。在第一個方法中，將兩張透明片疊合可以解碼出第一張秘密影像；將其中一張透明片平移後，再和另一張透明片疊合，則可以解碼出第二張秘密影像。在第二方法中，將兩張透明片疊合可以解碼出第一張秘密影像；將其中一張透明片翻轉平移後，再和另一張透明片疊合，則可以解碼出第二張秘密影像。在第三個方法中，將其中一張透明片旋轉平移後，再和另一張透明片疊合，則可以解碼出第一張秘密影像；將其中一張透明片旋轉平移後，再將另一張透明片翻轉，兩者疊合後可以解碼出第二張秘密影像。
接著，我們將上述的方法和多項式型分享結合，將秘密檔案透過多項式型分享藏進透明片中，延伸成二合一且有兩種解碼選項的方法。在這個方法中，第一個解碼選項是將透明片或是翻轉或是平移，再將兩張透明片疊合，則能夠解碼出兩張秘密影像。第二個解碼選項是將透明片們透過電腦分析，藉由電腦計算擷取出藏進透明片的秘密檔案。

關鍵字

視覺加密 ； 多項式型分享 ； 資訊隱藏

並列摘要

First, we propose a translated VC method, a translated FVC method, and a rotated version of our translated FVC method. In translated FVC method, one secret image can be decoded by stacking two transparencies together; the other one secret image can be decoded by stacking one translated transparency and the other one transparency. In ordinary translated FVC method, one secret image can be decoded by stacking two transparencies together; the other one secret image can be decoded by stacking one flipped and translated transparency and the other one transparency. In the rotated version of translated FVC method, one secret image can be decoded by stacking one transparency and the other one rotated and translated transparency; the other one secret image can be decoded by one flipped transparency and the other one rotated and translated transparency.
Then, we combine translated VC and FVC with PSS to present a two-in-one two-decoding-options images sharing method. The one decoding option is to decrypt multiple secret images by human visibility from translated VC or FVC; and the other decoding option is using computer to decrypt secret files by information extracted from transparencies.

並列關鍵字

visual cryptography ； polynomial-style sharing ； information hiding

參考文獻

[2] G. Ateniese, C. Blundo, A. De Santis, D.R. Stinson, “Contrast optimal threshold visual cryptography schemes,” SIAM J. Discrete Math., 16 (2003), pp. 224–226.

[3] C.N. Yang, “New visual secret sharing schemes using probabilistic method,” Pattern Recognition Lett., 25 (4) (2004), pp. 481–494.

[4] C.C. Thien, J.C. Lin, “Secret image sharing,” Comput. Graphics, 26 (5) (2002), pp. 765–770.

[5] A. Shamir, “How to share a secret,” Commun. ACM 1979, 22 (11) (1979), pp. 612–613.

[6] C.C. Thien, J.C. Lin, “An image-sharing method with user-friendly shadow images,” IEEE Trans. Circuits Syst. Video Technol., 13 (12) (2003), pp. 1161–1169.