数字版权保护（DRM）技术标准的比较研究
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摘要
信息时代，新的网络及数字化环境给传统意义上的版权带来了重大挑战。数字版权保护(DRM)技术是近几年国际上出现的一种融加密、签名、摘要、PKI公钥体制、DOI、XML、元数据、电子支付为一体的新兴技术，并被视为数字化时代解决版权问题的可能方案。与传统对数字化内容进行简单加密限制或访问控制不同，DRM力图协调保护知识产权与方便信息获取之间的矛盾，打造数字化内容的新型电子商务模式，使买卖双方达成双赢的结果。
本文从比较的角度对DRM技术进行研究。首先，对DRM技术的产生背景、基本概念、国内外DRM研究进展进行了综述，对比了国内外研究的差距，论述了对DRM技术标准进行比较研究的重要意义。其次，对加密、签名、摘要、PKI公钥体制、DOI、XML、元数据等DRM技术基础，以及DRM总体构架作了简要介绍，并比较了两种不同的构架模型。
在任何信息系统的开发中，需求分析都是最基础、最重要的一个环节。DRM作为一个大的技术体制，同样也不例外。由于需求的可变性及潜在性，正确认识与理解需求往往并非易事；对DRM进行需求收集与分析的结果，也在不断地发展与变化。本文列举了W3C、AAP、MPEG、OeBF、OASIS等行业标准化组织收集的不同需求文本，并从详尽性、抽象性、重合度、组织背景与利益倾向等方面比较了它们的异同。
权利表达语言(Rights Expression Language,REL)是DRM技术体系的关键与核心部分。ODRL与XrML是目前国际上两种主要的、互相竞争的权利表达语言，本文从需求符合度、核心概念、层次性、易理解性、成熟度、可扩展性、市场占有率、专利权限制等方面比较了它们的异同；并简单介绍了DPRL、XMCL、XACML、LicenseScript等其他权利语言。
DRM技术主要有两大应用领域，一类是电子书及电子文档，另一类是视频与音频流媒体。本文对这两类典型应用中的主要DRM系统和产品，包括EBX、Adobe、方正Apabi、Windows Media DRM、Real Helix DRM系统设计和特性作了扼要陈述。
作为比较研究的结果，本文末尾对现有DRM技术与产品的不足进行了分析；提出了建设完善的DRM技术标准应解决的若干矛盾；对未来DRM技术标准可能的前景、趋势进行了推测。提出了一个权利语言抽象描述框架，试图解决权利表达的互操作性问题。最后，针对我国DRM技术研究、开发与应用的落后状况，提出了引进国外先进技术、建立开放合作的DRM知识形成体系、开发具有自主知识产权的技术标准和产品等应对策略。
The freshly new digital and Internet environment of our information era have posed great threat to the so-called copyright. DRM (Digital Rights Management) is a new technology emerged in recent years which is seen as a solution to the digital copyright. DRM is different from the ever widely used limitation by encryption or access control methodology in that, it makes efforts to balance between intellectual property protection and the prompt acquisition of information. It enables new e-commerce models for digital content, trying out to reach a win-win result through that.
This paper conducts a comparative research to DRM technologies. First it gives an overview to the background, typical definitions, as well as international and domestic progress of DRM. It shows the gap between international and domestic DRM application, and lists the value of this comparative research. After that, a brief introduction to several former techniques which bases DRM and two different DRM architecture models are also presented.
Requirement analysis is critical to every information system, and that has no exception for DRM. It is not easy to recognize or understand those requirements because they are always variable and implicit. This paper lists DRM requirements from five standardization groups-W3C, AAP, MPEG, OeBF, OASIS, as well as make a comparison to them from several angles.
Rights Expression Language is a key part of DRM. ODRL and XrML are two major competing REL. This paper shows the similarity and difference of these two from many aspects, such as their core concepts, fidelity to the expressed DRM requirements, layer of presentation, eligibility, maturity, extensibility, market performance, and patent limitation. By the way, give an overview to some other typical DRM languages.
There are two major applications for DRM, namely eBooks and video/audios. The designs and system features of five leading DRM products, including EBX, Adobe, Apabi of Founder Electronics, Microsoft Windows Media DRM, and Real Helix DRM are briefly listed.
As a result of this comparison research, this paper presents the drawbacks of current DRM techniques and products, poses several paradoxes which have to be confronted for a better DRM solution, indicates the outlook of future DRM. An abstract framework of Rights Expression Language is proposed to add more flexibility and interoperability. Also, measures are suggested to be taken as next step for us dealing with the unfavorable situation.
本文从比较的角度对DRM技术进行研究。首先，对DRM技术的产生背景、基本概念、国内外DRM研究进展进行了综述，对比了国内外研究的差距，论述了对DRM技术标准进行比较研究的重要意义。其次，对加密、签名、摘要、PKI公钥体制、DOI、XML、元数据等DRM技术基础，以及DRM总体构架作了简要介绍，并比较了两种不同的构架模型。
在任何信息系统的开发中，需求分析都是最基础、最重要的一个环节。DRM作为一个大的技术体制，同样也不例外。由于需求的可变性及潜在性，正确认识与理解需求往往并非易事；对DRM进行需求收集与分析的结果，也在不断地发展与变化。本文列举了W3C、AAP、MPEG、OeBF、OASIS等行业标准化组织收集的不同需求文本，并从详尽性、抽象性、重合度、组织背景与利益倾向等方面比较了它们的异同。
权利表达语言(Rights Expression Language,REL)是DRM技术体系的关键与核心部分。ODRL与XrML是目前国际上两种主要的、互相竞争的权利表达语言，本文从需求符合度、核心概念、层次性、易理解性、成熟度、可扩展性、市场占有率、专利权限制等方面比较了它们的异同；并简单介绍了DPRL、XMCL、XACML、LicenseScript等其他权利语言。
DRM技术主要有两大应用领域，一类是电子书及电子文档，另一类是视频与音频流媒体。本文对这两类典型应用中的主要DRM系统和产品，包括EBX、Adobe、方正Apabi、Windows Media DRM、Real Helix DRM系统设计和特性作了扼要陈述。
作为比较研究的结果，本文末尾对现有DRM技术与产品的不足进行了分析；提出了建设完善的DRM技术标准应解决的若干矛盾；对未来DRM技术标准可能的前景、趋势进行了推测。提出了一个权利语言抽象描述框架，试图解决权利表达的互操作性问题。最后，针对我国DRM技术研究、开发与应用的落后状况，提出了引进国外先进技术、建立开放合作的DRM知识形成体系、开发具有自主知识产权的技术标准和产品等应对策略。
The freshly new digital and Internet environment of our information era have posed great threat to the so-called copyright. DRM (Digital Rights Management) is a new technology emerged in recent years which is seen as a solution to the digital copyright. DRM is different from the ever widely used limitation by encryption or access control methodology in that, it makes efforts to balance between intellectual property protection and the prompt acquisition of information. It enables new e-commerce models for digital content, trying out to reach a win-win result through that.
This paper conducts a comparative research to DRM technologies. First it gives an overview to the background, typical definitions, as well as international and domestic progress of DRM. It shows the gap between international and domestic DRM application, and lists the value of this comparative research. After that, a brief introduction to several former techniques which bases DRM and two different DRM architecture models are also presented.
Requirement analysis is critical to every information system, and that has no exception for DRM. It is not easy to recognize or understand those requirements because they are always variable and implicit. This paper lists DRM requirements from five standardization groups-W3C, AAP, MPEG, OeBF, OASIS, as well as make a comparison to them from several angles.
Rights Expression Language is a key part of DRM. ODRL and XrML are two major competing REL. This paper shows the similarity and difference of these two from many aspects, such as their core concepts, fidelity to the expressed DRM requirements, layer of presentation, eligibility, maturity, extensibility, market performance, and patent limitation. By the way, give an overview to some other typical DRM languages.
There are two major applications for DRM, namely eBooks and video/audios. The designs and system features of five leading DRM products, including EBX, Adobe, Apabi of Founder Electronics, Microsoft Windows Media DRM, and Real Helix DRM are briefly listed.
As a result of this comparison research, this paper presents the drawbacks of current DRM techniques and products, poses several paradoxes which have to be confronted for a better DRM solution, indicates the outlook of future DRM. An abstract framework of Rights Expression Language is proposed to add more flexibility and interoperability. Also, measures are suggested to be taken as next step for us dealing with the unfavorable situation.
引文
[1] 李顺德．数字图书馆与知识产权保护．图书情报工作，2002(12)
[2] 陈传夫．解决网络与数字图书馆知识产权问题应坚持什么立场．图书情报工作，2002(12)
[3] 刘可静．知识产权与图书情报工作．图书情报工作，2002(12)
[4] SMILChina, 微软公司．什么是 Windows Media DRM. http://www.wms.cn/technologies/wm7/drm/what.htm, visited on March 31, 2004
[5] 新浪网．DRM技术推动eBook产业发展．http://www.apabi.com/news/news 2/20030702 4.htm, visited on March 31, 2004
[6] 张珺．方正阿帕比DRM获信息产业重大技术发明奖．中华读书报，2003．12．03．转引自 http://www.apabi.com/news/news 2/20031203.htm, visited on April 29, 2004
[7] 北大方正电子有限公司．方正Apabi重要文档防扩散系统．http://www.founder.com.cn/cn/product/showproduct.asp?id=132, visited on March 31,2004
[8] 北京易控微网科技有限公司．数字版权管理(DRM)系统解决方案．http://www.econtrolnet.com/tech/tech.htm, visited on March 31, 2004
[9] 德国威博系统股份公司上海代表处．威博产品CodeMeter http://www.wibu.com.cn/product/codemeter.htm, visited on April 30, 2004
[10] 中科院华建集团．数字版权管理(DRM)解决方案．http://www.hitek.com/iieiue/digital/digitail.htm, visited on April 30, 2004
[11] 中华在线．产品专区—DRM数字加密系统(DRMEncoder)．http://www.onlinecn.net/product/drm.htm, visited on April 30, 2004
[12] 张晓林．数字权益管理技术．现代图书情报技术，2003(5)
[13] 刘艳．版权技术锁定唱片业未来．互联网周刊，2003．3．10
[14] 杨鑫．唱片业暗流涌动．2003．3．10
[15] 任寰，魏衍亮．国外数据库立法与案例之评析．知识产权，2003(2)
[16] 陈燕编译．电子出版控制的一项新工具：DOI系统—来自英国的报道．图书馆杂志，2000(2)
[17] IDF(the International DOI Foundation). the Digital Object Identifier System. http://www.doi.org/, visited on April 18, 2004
[18] 陈燕．电子出版物新宠—网络电子图书．图书馆杂志，2000(10)
[19] 冯洁音．新概念图书—Ebook．图书馆杂志，2000(10)
[20] 孙慧娥．形形色色的电子图书实验．图书馆杂志，2000(10)
[21] 张春红，蒋刚苗．中文电子图书比较研究．大学图书馆学报，2002(1)
[22] 赵继海．DRM技术的发展及其对数字图书馆的影响．大学图书馆学报，2002(1)
[23] [美]Andrew Nash等著，张玉清等译．公钥基础设施(PIG)实现和管理电子商务安全．北京：清华大学出版社，2002．12
[24] 李书宁，马明霞．数字水印技术在数字图书馆安全问题中的应用．现代图书情报技术，2002(1)
[25] W3C Workshop on Digital Rights Management for the Web. Workshop Report. http://www.w3.org/2000/12/drm-ws/, 22-23 January 2001, visited on Sep. 23rd, 2003
[26] Willms Buhse. Implications of Digital Rights Management for the Online Music-A Business Perspective. ACM No.8 workshop (DRM workshop) 2002 symposium
[27] Stefan Bechtold. From Copyright to Information Law-Implications of Digital Rights Management. ACM No.8 workshop(DRM workshop) 2002 symposium
[28] Ernest Miller,Joan Feigenbaum.Taking the Copy out of Copyright. ACM No.8 workshop (DRM workshop) 2002 symposium
[29] 王建业，周振国，陈森发．Intemet X.509 PKI深入讨论与分析．计算机应用研究，2003(2)
[30] 罗良道．浅论数字化信息的网上销售．图书馆杂志，2000(5)
[31] [美]Andrew Nash等著，张玉消等译．公钥基础设施(PIG)实现和管理电子安全．北京：清华大学出版社，2002．12
[32] [美]Mohan Atreya等著，贺军等译．数字签名．北京：清华大学出版社，2003．1
[33] [美]Michael Morrison等著，陆新年、陆新宇等译．XML揭秘—入门·应用·精通．北京：清华大学出版社，2001．6
[34] 刘嘉．元数据导论．北京：华艺出版社，2002．1
[35] 张建明，文学军．数字版权管理系统的原理与应用．现代图书情报技术，2004(2)
[36] 戴元军．信息隐藏与数字水印技术． http://www-900.ibm.com/developerWorks/cn/security/1-info/index.shtml, visited on March31, 2004
[37] Renato Iannella.Digital Rights Management(DRM) Architectures. http://www.dlib.org/dlib/june01/iannella/06iannella.html, visited on March 31, 2004
[38] AAP(Association of American Publishers). Digital Rights Management for Ebooks: Publisher Requirements. http://www.publishers.org/digital/drm.pdf, visited on March 31, 2004
[39] MPEG(Moving Picture Experts Group). Requirements for Rights Data Dictionary and Rights Expression Language.
http://www.chiariglione.org/mpeg/working documents/mpeg-21/requirements/RDD&REL requirements.zip, visited on April 18, 2004
[40] MPEG (Moving Picture Experts Group). MPEG-21 Requirements. http://www.chiariglione.org/mpeg/working documents/mpeg-21/ipmp/requirements.zip, visited on April 18, 2004
[41] Rights and Rules Working Group Open eBook Forum. OeBF Rights Grammar Requirements. http://www.openebook.org/specifications/coodinatedfiles/OeBF%20Rights%20Grammar %20Requircments.doc, visited on April 18, 2004
[42] OASIS RLTC. Rights Language Technical Committee (RLTC) Requirements. http://xml.coverpages.org/RLTCRequirements0828.doc, visited on April 18, 2004
[43] MPEG (Moving Picture Experts Group). MPEG-21 Overview v.5. http://www.chiariglione.org/mpeg/standards/mpeg-21/mpeg-21.htm, visited on April 18, 2004
[44] ODRL Initiative, edited by Renato Iannella. Open Digital Rights Language (ODRL) Version 1.1. http://www.w3.org/TR/odrl/, visited on April 18, 2004
[45] ODRL Initiative. ODRL Overview Brochure. http://odrl.net/docs/ODRL-brochure.pdf, visited on April 18, 2004
[46] ContentGuard. eXtensible rights Markup Language (XrML) 2.0 Specification. http://www.xrml.org/, visited on April 18, 2004
[47] Cheun Ngen Chong, Sandro Etalle, and Pieter H Hartel.Comparing Logic-based and XML-based Rights Expression Languages. https://doc.telin.nl/dscgi/ds.py/Get/File-33671/comparison.pdf, visited on April 18, 2004
[48] Grace Agnew. Rights Expression Languages: Overview. http://xml.coverpages.org/AgnewREL200209.pdf, visited on April 18, 2004
[49] Steven Rowat. DRM Direct From Creator To User: ODRL or XrML? Comments about free, open, and transparent DRM and micropayment standards. http://www.rowatworks.com/Overview Indexes/DRM Micropayment ODRL XrML.htm 1, visited on April 18, 2004
[50] Gord Larose. Drm Standards. http://www.info-mech.com/drm standards.html, visited on April 18, 2004
[51] Grace Agnew. An introduction to DRM: Part 1. http://www.oclc.org/community/topics/rights/perspectives/archiyes/agnew1.htm, visited on April 18, 2004
[52] Karen Coyle. Digital Rights Management-Part 3 Rights Expression Language. http://www.kcoyle.net/drm basics3.html, visited on April 18, 2004
[53] Bill Rosenblatt.2003 in Review: DRM Standards.
http://www.drmwatch.com/standards/article.php/3295291, visited on April 18, 2004
[54] Michael Fromm, Hermann Gruber, Manfred Schutz. Evaluation of Digital Rights Management Systems. http://wi.wu-wien.ac.at/people/Guth/evaluation%20of%20drm%20systems.pdf, visited on April 18, 2004
[55] Book Industry Study Group. The Electronic Book Exchange System (EBX) Version 0.8. httP://xml.coverpages.org/ebx-spec08.pdf, visited on April 24, 2004
[56] RealNetworks 中国网站．产品与服务——HELIX DRM 10. http://china.realnetworks.com/products/drm/index.html, visited on April 24, 2004
[57] RealNetworks. HELIX DRM 10 FROM REAL. http://www.realnetworks.com/products/drm/index.html, visited on April 24, 2004
[58] SMILChina 以及微软公司．数字版权管理 DRM. http://www.windowsmedia.cn/technologies/drm/index.htm, visited on April 24, 2004
[59] Microsoft Corporation. Windows Media 数字版权管理9系列．http://www.microsoft.com/windows/windowsmedia/CN/9series/drm.asp, visited on April 24, 2004
[60] Adobe Systems. Adobe Content Server 3.0. http://www.adobe.com/products/contentserver/main.html, visited on April 24, 2004
[61] Adobe Systems. Adobe Content Server 3.0. http://www.chinese-s.adobe.com/products/contentserver/main.html, visited on April 24, 2004
[62] RealNetworks. RealSystem Media Commerce Suite Technical White Paper. http://docs.real.com/docs/drm/DRM WP1.pdf, visited on April 24, 2004
[63] OASIS. XML and Digital Rights Management (DRM). http://xml.coverpages.org/drm.html, visited on April 24, 2004
[64] INDECS. AboutFramework Ltd. http://www.indecs.org/, visited on April 29, 2004
[65] EDItEUR. ONIX for Books. http://www.editeur.org/onix.html, visited on April 29, 2004
[66] 虚拟世界的“硬币”．文汇报，2004．4．18，第5版科技文摘专刊
[2] 陈传夫．解决网络与数字图书馆知识产权问题应坚持什么立场．图书情报工作，2002(12)
[3] 刘可静．知识产权与图书情报工作．图书情报工作，2002(12)
[4] SMILChina, 微软公司．什么是 Windows Media DRM. http://www.wms.cn/technologies/wm7/drm/what.htm, visited on March 31, 2004
[5] 新浪网．DRM技术推动eBook产业发展．http://www.apabi.com/news/news 2/20030702 4.htm, visited on March 31, 2004
[6] 张珺．方正阿帕比DRM获信息产业重大技术发明奖．中华读书报，2003．12．03．转引自 http://www.apabi.com/news/news 2/20031203.htm, visited on April 29, 2004
[7] 北大方正电子有限公司．方正Apabi重要文档防扩散系统．http://www.founder.com.cn/cn/product/showproduct.asp?id=132, visited on March 31,2004
[8] 北京易控微网科技有限公司．数字版权管理(DRM)系统解决方案．http://www.econtrolnet.com/tech/tech.htm, visited on March 31, 2004
[9] 德国威博系统股份公司上海代表处．威博产品CodeMeter http://www.wibu.com.cn/product/codemeter.htm, visited on April 30, 2004
[10] 中科院华建集团．数字版权管理(DRM)解决方案．http://www.hitek.com/iieiue/digital/digitail.htm, visited on April 30, 2004
[11] 中华在线．产品专区—DRM数字加密系统(DRMEncoder)．http://www.onlinecn.net/product/drm.htm, visited on April 30, 2004
[12] 张晓林．数字权益管理技术．现代图书情报技术，2003(5)
[13] 刘艳．版权技术锁定唱片业未来．互联网周刊，2003．3．10
[14] 杨鑫．唱片业暗流涌动．2003．3．10
[15] 任寰，魏衍亮．国外数据库立法与案例之评析．知识产权，2003(2)
[16] 陈燕编译．电子出版控制的一项新工具：DOI系统—来自英国的报道．图书馆杂志，2000(2)
[17] IDF(the International DOI Foundation). the Digital Object Identifier System. http://www.doi.org/, visited on April 18, 2004
[18] 陈燕．电子出版物新宠—网络电子图书．图书馆杂志，2000(10)
[19] 冯洁音．新概念图书—Ebook．图书馆杂志，2000(10)
[20] 孙慧娥．形形色色的电子图书实验．图书馆杂志，2000(10)
[21] 张春红，蒋刚苗．中文电子图书比较研究．大学图书馆学报，2002(1)
[22] 赵继海．DRM技术的发展及其对数字图书馆的影响．大学图书馆学报，2002(1)
[23] [美]Andrew Nash等著，张玉清等译．公钥基础设施(PIG)实现和管理电子商务安全．北京：清华大学出版社，2002．12
[24] 李书宁，马明霞．数字水印技术在数字图书馆安全问题中的应用．现代图书情报技术，2002(1)
[25] W3C Workshop on Digital Rights Management for the Web. Workshop Report. http://www.w3.org/2000/12/drm-ws/, 22-23 January 2001, visited on Sep. 23rd, 2003
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