秘密分享意指一份重要主機密資訊被拆成兩份以上次機密訊息，在未達解開秘密基本需求數前，無法單純透過次秘密訊息得知原本機密資訊。多重秘密分享則是讓秘密分享參與者持有一份次機密訊息，即有能力還原多份主機密資訊。本文提出3種秘密分享技術應用於影像分享中，第1種方法讓分享影像解密後之還原影像與原機密影像完全相同，第2種則可以讓參與者僅持1張分享影像資訊即有能力還原多份機密影像，第3種為參與者持一張分享影像資訊，則可以令還原機密影像與原機密影像完全相同不失真之多張機密影像分享。經過實驗及執行結果，本文方法可讓單張機密影像不失真還原外，並進一步達成多張機密影像分享及無失真還原，証明本文方法非常有效且安全性足夠之方法。

A secret sharing scheme divides an important secret message to n shares for each participant. The important secret message cannot be reconstructed when we collect less than threshold shares, say t shares. That is, anyone observes no information about the secret message from only one share. A multi-secret sharing approach lets one participant reconstruct many secret messages from only one share. In this paper, we propose three methods for sharing digital images. In the first method, we can perfectly reconstruct the secret image. The second method can reconstruct many secret images when each participant only preserves one share. However, the reconstructed image is slightly different with the source image. In the third method, we adopt hash function to propose a multistage secret image sharing that the reconstructed image is consistent with the source image. Experimental results show that the proposed approach can reduce the possessing load efficiently but secure enough.

摘要 I
Abstract II
誌 謝 III
目 錄 IV
圖 目 錄 V
表 目 錄 VI
第一章 緖論 1
第一節 研究動機 1
第二節 研究目的 2
第三節 論文架構 3
第二章 單張機密影像之分享 4
第一節 Shamir 秘密分享方法 4
第二節 機密影像分享 5
第三節 無失真性機密影像之分享 9
第四節 實驗結果及比較 14
第三章 多重機密影像分享 18
第一節 多重機密影像之分享方法 18
第二節 實驗結果及比較 24
第四章 基於雜湊之多重機密影像分享 27
第一節 多重秘密分享方法 27
第二節 基於雜湊之多重機密影像分享方法 28
第三節 實驗結果及比較 33
第五章 安全性分析 37
第六章 結論與未來研究方向 40
第七章 參考文獻 42

中文
[1] 傅文殷、陳建彰
2005 植基於多維空間的機密影像分享方法，玄奘大學資訊管理學系碩士論文。
[2] 楊吳泉
1997 現代密碼學入門與程式設計，台北：全華。
西文
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