吳家麟臺灣大學：資訊工程學研究所黃俊翔Huang, Chun-HsiangChun-HsiangHuang2007-11-262018-07-052007-11-262018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/54122相較於傳統類比內容的諸多限制，數位內容兼具了品質優異、易於複製儲存、傳輸迅速以及容易編輯管理等優點。隨著數位內容的製作/複製/剪輯技術不斷進步與普及，數位形式的多媒體內容在質與量方面都已經有了長足的進步。再加上網際網路使用者數量的爆炸性成長與基礎網路設施的日益健全，數位內容的傳播儼然已經成為一種重要的全球性新興溝通媒介。然而，儘管相關的壓縮及通訊技術已經趨近成熟，目前的數位內容產業仍然無法替使用者的日常生活帶來預期中的革命性進步。除了缺乏技術面的整體標準架構之外，最重要的關鍵就在於與數位內容有關的智慧財產權問題。 數位內容提供者是否願意提供大量高品質的內容，是數位內容產業能否蓬勃發展的決定性因素。但數位內容可完美複製及透過網路迅速傳遞的優異特性，卻也為不肖犯罪者在侵害數位內容創作者與提供者的智慧財產財權時大開方便之門，並進而導致數位內容提供業者對於進一步地投入裹足不前。基於上述理由，數位權利管理相關科技與措施遂應運而生，希冀能透過技術，法律以及商業面的配合，徹底保護所有參與者在數位內容價值鏈中應享的權利、隱私與適當利益。 數位權利管理技術的主要基礎技術大致可分為三類：加密/解密技術，數位浮水印技術以及數位權利語言。以密碼學為基礎的加解密技術一直被視為安全用途的最後屏障，並且已相當成熟，不過在數位權利管理這項應用上，仍有新的問題與發展值得注意。數位浮水印技術則是為了保護數位內容這項用途所開發出來的新技術，其最初的用意就在於彌補加解密技術應用範圍的不足。隨著學界的不斷投入，數位浮水印的各種基礎理論與其它應用也逐漸完備，不過仍有釵h尚未找到滿意解答的相關問題值得繼續研究，例如設計出可改善浮水印效能的最佳化浮水印嵌入方式，因為幾何處理導致浮水印消失的問題，如何在公布浮水印演算法的細節後持續抵抗惡意移除攻擊…等等。至於數位權利語言，則是用來定義數位內容可在怎樣的條件下，由哪些合法使用者或裝置，進行哪些被允釭犒B算或消費動作。目前已經有釵h權利語言的相關標準為各界所提出。 在本論文中，我們將重點放在對於數位浮水印技術的討論，及其在數位權利管理架構中的應用。首先，我們針對了數位浮水印技術的現況進行簡介，希望能對數位浮水印技術的全貌與遭遇到的問題有更清楚的瞭解。接著，我們針對數位浮水印技術的效能與安全性進行探討。我們提出了以演化計算為基礎的不可見式浮水印效能改良方式，並透過實驗證明其改良效果。這項作法不僅可有效地改良浮水印技術的效能，並且在系統架構上具有釵h優越的性質。接著，我們根據對於可見式浮水印的觀察，在最少使用者干預的條件下進行了有效的攻擊，並提出了幾點安全上的改進意見。最後，我們提出了一套可透過網路進行數位內容交易與散佈的數位權利管理架構，並完成了以影像為保護內容的實作，藉此來驗證各種數位權利管理基礎技術的實際應用效果。Digital watermarking is regarded as a potential solution against the content piracy problem and is an important research topic in the past decade. After years of study, capabilities and limits of digital watermarking technologies have become more and more clear, and various applications of digital watermarking have been discovered. Designing an optimal watermarking scheme under certain fidelity/robustness constraints is still an open problem in the literature of digital watermarking. In this thesis, optimal watermark embedding is modeled as an optimization problem, and evolutionary computational skills are adopted to solve it. The fidelity and robustness requirements of digital watermarking are used as objective functions that guide the optimization procedure, respectively. As a result, a watermarking performance enhancement scheme is successfully proposed and evaluated. Furthermore, the proposed scheme possesses many desirable characteristics, such as asymmetric and independent embedding/extraction architecture that facilitates both optimal embedding and real-time extraction, blind watermark extraction, … etc. Visible watermarking is another protective mechanism in which visible but unobtrusive copyright patterns are embedded within contents that need to be protected. Attacking visible watermarking schemes means successfully recover embedded images or videos, under the requirement that only minimal user intervention is involved. In the proposed attacking procedures, copyright patterns consisting of thin lines are recovered by inpainting techniques. Furthermore, flat embedded areas are recovered by propagating color information from neighboring unmarked areas, and remaining areas are recovered by prediction using nearby recovery information. Acceptable recovered images can be obtained by the proposed attacking scheme. Suggestions that enhance the security of existing visible watermarking schemes are given, and simultaneously using both visible watermarking and fragile watermarking schemes are proposed as a solution against malicious attacks. In fact, the goal of content protection cannot be achieved with the watermarking technology alone. Digital rights management (DRM) – a combination of cryptographic techniques, digital watermarking schemes and rights specification languages – is a complete solution against content piracy. In this thesis, important DRM related standards, such as relevant parts within MPEG-21, CPPM/CPRM, CPSA, DTCP, HDCP, …etc, are surveyed and introduced. Furthermore, important commercial DRM systems, legislative measures and critical opinions are also included. In addition, a DRM framework protecting image distribution over digital networks and guaranteeing rights of both buyers and sellers are proposed and implemented. In this thesis, both optimal invisible watermark embedding and the security of visible watermarking schemes are discussed. Furthermore, a proprietary DRM framework is also implemented. Solving remaining open problems related to digital watermarking and DRM developments are future research directions of the author.CHAPTER 1 DIGITAL WATERMARKING: PAST, PRESENT AND FUTURE 23 1.1 BASICS ABOUT DIGITAL WATERMARKING 24 1.2 CLASSIFICATIONS OF DIGITAL WATERMARKING 27 1.3 APPLICATIONS OF DIGITAL WATERMARKING 30 1.4 REQUIREMENTS OF DIGITAL WATERMARKING 33 1.5 MODELS OF DIGITAL WATERMARKING 36 1.6 SOME WELL-KNOWN WATERMARKING SCHEMES 38 1.6.1 THE SPREAD-SPECTRUM WATERMARKING 38 1.6.2 HSU AND WU’S DCT-BASED WATERMARKING SCHEME 39 1.6.3 COCKTAIL WATERMARKING 41 1.6.4 QUANTIZATION WATERMARKING 41 1.7 THE FUTURE OF WATERMARKING 42 CHAPTER 2 TOWARD OPTIMAL INVISIBLE WATERMARKING 45 2.1 OVERVIEW 45 2.2 GENETIC ALGORITHMS AND WATERMARKING 48 2.3 FIDELITY ENHANCEMENT BY FINDING BEST WATERMARK EMBEDDING POSITIONS 49 2.3.1 FIDELITY ENHANCEMENT FOR BLOCK TRANSFORM WATERMARKING 49 2.3.2 FIDELITY ENHANCEMENT FOR SPREAD-SPECTRUM WATERMARKING 58 2.3.3 SYSTEMATICALLY ENHANCING BOTH FIDELITY AND ROBUSTNESS OF EXISTING WATERMARKING SCHEMES 69 2.3.4 EFFICIENCY-RELATED ISSUES FOR THE PROPOSED FIDELITY ENHANCING APPROACH 70 2.3.5 ARCHITECTURE INFEASIBILITY FOR REAL-WORLD APPLICATIONS 71 2.4 ROBUSTNESS ENHANCEMENT BY SEARCHING FOR THE BEST EMBEDDED RESULT DIRECTLY 72 2.4.1 THE PROPOSED ROBUSTNESS ENHANCEMENT ARCHITECTURE AND IMPLEMENTATION DETAILS 73 2.4.2 IMPROVEMENTS IN SYSTEM ARCHITECTURE AND APPLICABILITY 82 2.5 GETTING CLOSER TOWARD OPTIMAL INVISIBLE WATERMARKING 83 CHAPTER 3 VISIBLE WATERMARKING: ATTACKS AND IMPLICATIONS 85 3.1 VISIBLE WATERMARKING VS. INVISIBLE WATERMARKING 86 3.2 STATE-OF-THE-ART OF VISIBLE WATERMARKING 87 3.3 A GENERAL MODEL OF VISIBLE WATERMARKING 89 3.4 ATTACKING VISIBLE WATERMARKING SCHEMES 91 3.4.1 IMPORTANT OBSERVATIONS 91 3.4.2 ATTACKING SIMPLE WATERMARKS WITH IMAGE RECOVERY TECHNIQUES 92 3.4.3 ATTACKING GENERAL WATERMARKS WITH PROPOSED ALGORITHMS 96 3.4.4 ATTACKING OTHER ENHANCED WATERMARKING SCHEMES 107 3.5 DISCUSSIONS 111 3.5.1 THE EFFECT OF WATERMARKED AREAS SELECTION 111 3.5.2 CAN VISIBLE WATERMARKING SCHEMES PROVIDE SECURE COPYRIGHT PROTECTION? 112 3.6 CONCLUSIONS AND FUTURE WORKS 113 CHAPTER 4 DIGITAL RIGHTS MANAGEMENT: TRENDS, STANDARDS AND IMPLEMENTATIONS 115 4.1 BASICS OF DIGITAL RIGHTS MANAGEMENT 115 4.2 SURVEY OF CURRENT DRM SYSTEMS 117 4.3 CHARACTERISTICS OF A DRM SYSTEM 122 4.4 TECHNOLOGICAL BASES OF A DRM SYSTEM 123 4.5 OVERVIEW OF MPEG-21 PART 4: IPMP 124 4.6 THE PROPOSED DRM FRAMEWORK 126 4.7 OTHER IMPORTANT DRM STANDARDS 129 4.7.1 CPPM/CPRM 129 4.7.2 XRML 131 4.7.3 DTCP AND HDCP 132 4.7.4 CPSA 132 4.8 IMPORTANT LEGISLATIVE CONCERNS ABOUT DRM 133 4.9 DEBATES ABOUT DRM 135 CHAPTER 5 CONCLUSIONS 137 5.1 CONTRIBUTIONS 137 5.2 CONCLUSIONS AND FUTURE WORK 138 BIBLIOGRAPHY 1396136682 bytesapplication/pdfen-US數位權利管理架構數位浮水印robustnessfidelityDRM frameworksDigital watermarkingthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54122/1/ntu-93-D88526011-1.pdf