Pramod A. Jamkhedkar, G. Heileman, I. Martínez-Ortiz
In this paper we consider the functionality that a rights expression language (REL) should provide within a digital rights management (DRM) environment. We begin by noting the dearth of applications that make use of RELs, despite the fact that they have now been available since the late 1990's. We posit that one of the main impediments to the use of RELs is the complexity associated with understanding and using them. This results from the fact that the functionality needed to handle a wide variety of possible DRM scenarios is typically built into a REL, and it is often difficult to cleanly partition out only those pieces needed by a particular DRM application. Basing DRM system design on a layered architecture provides one way of achieving a partitioning and points to the need for a simple REL that is exclusively responsible for the expression of rights, while pushing much of the functionality found in current RELs into higher system layers. In order to demonstrate the usefulness of this approach, we provide an example implementation dealing with DRM-based negotiation.
{"title":"The problem with rights expression languages","authors":"Pramod A. Jamkhedkar, G. Heileman, I. Martínez-Ortiz","doi":"10.1145/1179509.1179522","DOIUrl":"https://doi.org/10.1145/1179509.1179522","url":null,"abstract":"In this paper we consider the functionality that a rights expression language (REL) should provide within a digital rights management (DRM) environment. We begin by noting the dearth of applications that make use of RELs, despite the fact that they have now been available since the late 1990's. We posit that one of the main impediments to the use of RELs is the complexity associated with understanding and using them. This results from the fact that the functionality needed to handle a wide variety of possible DRM scenarios is typically built into a REL, and it is often difficult to cleanly partition out only those pieces needed by a particular DRM application. Basing DRM system design on a layered architecture provides one way of achieving a partitioning and points to the need for a simple REL that is exclusively responsible for the expression of rights, while pushing much of the functionality found in current RELs into higher system layers. In order to demonstrate the usefulness of this approach, we provide an example implementation dealing with DRM-based negotiation.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127915919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we propose an alternative DRM technology for next-generation optical media. Instead of implementing a hard access control mechanism, we propose a scheme that monitors the behavior of users in a privacy-preserving manner, detects potential infringement actions and reacts in a graceful way, which is dependent on the severity of infringements. The scheme is based on blacklists of known unauthorized content and compromised players, which are maintained by content providers and shipped alongside the content. Most of the functionality is implemented by content code provided on the disc, allowing for player independent and flexible reactions.
{"title":"Graceful infringement reactions in DRM systems","authors":"S. Katzenbeisser, K. Kursawe, J. Talstra","doi":"10.1145/1179509.1179526","DOIUrl":"https://doi.org/10.1145/1179509.1179526","url":null,"abstract":"In this paper, we propose an alternative DRM technology for next-generation optical media. Instead of implementing a hard access control mechanism, we propose a scheme that monitors the behavior of users in a privacy-preserving manner, detects potential infringement actions and reacts in a graceful way, which is dependent on the severity of infringements. The scheme is based on blacklists of known unauthorized content and compromised players, which are maintained by content providers and shipped alongside the content. Most of the functionality is implemented by content code provided on the disc, allowing for player independent and flexible reactions.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127529337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Identification is a two part system comprising of a token or label (an identifier) that can be used to reference an entity and a process that can be used to create label-entity associations and verify that the reference and entity belong together. There are a number of identity systems for digital objects that provide identifiers (such as the Handle system, the DOI and URIs). However none of these systems provide verification services. The primary application for our proposed system is in a DRM system, where it is necessary to correctly match users' use licenses to the digital objects covered by the use licenses. In such a case, incorrect associations are effectively failures of the system, and could have wide ranging legal and economic impact, depending on the nature of the protected data.In this paper we present an identity system for digital objects that support verification and the related details such as the identifier format, the verification process as well as a protocol to create identifiers for digital objects.
{"title":"Verifiable digital object identity system","authors":"A. Arnab, A. Hutchison","doi":"10.1145/1179509.1179514","DOIUrl":"https://doi.org/10.1145/1179509.1179514","url":null,"abstract":"Identification is a two part system comprising of a token or label (an identifier) that can be used to reference an entity and a process that can be used to create label-entity associations and verify that the reference and entity belong together. There are a number of identity systems for digital objects that provide identifiers (such as the Handle system, the DOI and URIs). However none of these systems provide verification services. The primary application for our proposed system is in a DRM system, where it is necessary to correctly match users' use licenses to the digital objects covered by the use licenses. In such a case, incorrect associations are effectively failures of the system, and could have wide ranging legal and economic impact, depending on the nature of the protected data.In this paper we present an identity system for digital objects that support verification and the related details such as the identifier format, the verification process as well as a protocol to create identifiers for digital objects.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130854386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Through legislation and technology the film industry has been seeking to fully control usage of the bits it creates; their model is "restrictive" digital-rights management (DRM) that only allows the user to view the film rather than copy, edit, or create new content. Meanwhile, the experience that the Internet generation has of interacting with, rather than consuming, content, could be the basis for a new business for Hollywood: films that enable users to interact directly by putting themselves (and others) into the movie. In this paper we examine massive multi-player online role-playing games (MMORPGs), in which players exercise design technologies and tools that further their roles and play. MMORPGs are rapidly gaining audience share. We posit that non-restrictive, or exible, digital-rights management is in the movie industry's economic interest.
{"title":"Consumers, fans, and control: what the games industry can teach Hollywood about DRM","authors":"S. Landau, Renée Stratulate, Doug Twilleager","doi":"10.1145/1179509.1179511","DOIUrl":"https://doi.org/10.1145/1179509.1179511","url":null,"abstract":"Through legislation and technology the film industry has been seeking to fully control usage of the bits it creates; their model is \"restrictive\" digital-rights management (DRM) that only allows the user to view the film rather than copy, edit, or create new content. Meanwhile, the experience that the Internet generation has of interacting with, rather than consuming, content, could be the basis for a new business for Hollywood: films that enable users to interact directly by putting themselves (and others) into the movie. In this paper we examine massive multi-player online role-playing games (MMORPGs), in which players exercise design technologies and tools that further their roles and play. MMORPGs are rapidly gaining audience share. We posit that non-restrictive, or exible, digital-rights management is in the movie industry's economic interest.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122323965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In high-tech businesses ranging from Internet service providers to e-commerce websites and music stores like Apple iTun-es, there is considerable potential for collecting personal information about customers, monitoring their usage habits, or even exerting control over their behavior - for example, restricting what can be done with a purchased song. A privacy ceiling is an effective limit to these privacy intrusions, created by the perceived or actual legal liability of possessing too much information or control. As we show in this paper, the risk is not simply that of customer backlash, but liability for a customer's actions, owing to the ability to identify, report, or prevent them from taking those actions. In some cases high-tech businesses have been obligated to divulge their store of personal information or to police their customers at the demand of third parties; this unwanted result derives from the possession of too much information or control for the company's own good. We argue that vicarious infringement liability in particular creates a privacy ceiling, a point beyond which there is no economic incentive to intrude on a user's privacy; and, indeed, there is an incentive to architect one's business so that such intrusions are difficult or impossible.
{"title":"Vicarious infringement creates a privacy ceiling","authors":"Janice Y. Tsai, L. Cranor, S. Craver","doi":"10.1145/1179509.1179512","DOIUrl":"https://doi.org/10.1145/1179509.1179512","url":null,"abstract":"In high-tech businesses ranging from Internet service providers to e-commerce websites and music stores like Apple iTun-es, there is considerable potential for collecting personal information about customers, monitoring their usage habits, or even exerting control over their behavior - for example, restricting what can be done with a purchased song. A privacy ceiling is an effective limit to these privacy intrusions, created by the perceived or actual legal liability of possessing too much information or control. As we show in this paper, the risk is not simply that of customer backlash, but liability for a customer's actions, owing to the ability to identify, report, or prevent them from taking those actions. In some cases high-tech businesses have been obligated to divulge their store of personal information or to police their customers at the demand of third parties; this unwanted result derives from the possession of too much information or control for the company's own good. We argue that vicarious infringement liability in particular creates a privacy ceiling, a point beyond which there is no economic incentive to intrude on a user's privacy; and, indeed, there is an incentive to architect one's business so that such intrusions are difficult or impossible.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131640020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of Digital Rights Management (DRM) technologies for the enforcement of digital media usage models is currently subject of a heated debate. Content creators, owners and distributors argue that DRM technologies are needed to protect their Intellectual Property (IP) from unauthorized access. A counter argument from the Information Technology (IT) and Consumer Electronics (CE) industries states that DRM technologies are obstacles to innovation. Academic institutions add to the discussion by claiming that DRM technologies and associated legislation interfere with their academic mission. Yet another point of view is provided by consumer organizations who claim that DRM technology interferes with basic personal rights, such as the right to make back-up copies for personal use. Finally, national governments express concern that the deployment of DRM technology violates open market rules and regulations and is associated with anti-competitive behavior. This last issue has lately gained increased attention in a number of European countries. In this talk we argue that a number of the concern listed above can be resolved by introducing a sufficiently powerful DRM interoperability framework. In particular we discuss the CORAL DRM interoperability framework that allows multiple DRM systems to seamlessly work together while at the same time requiring minimal modification to participating DRM systems. After introducing the problem of DRM interoperability the following topics will be addressed: (1) approaches to DRM interoperability, (2) introduction to the CORAL architecture, (3) building ecosystems on top of Coral, (4) integrating DRM systems into CORAL and (5) deploying CORAL. We end the talk by going back to the initial problem statement, summarizing to what extent CORAL resolves the identified issues and what work remains to be done.
{"title":"On interoperability of DRM","authors":"T. Kalker","doi":"10.1145/1179509.1179519","DOIUrl":"https://doi.org/10.1145/1179509.1179519","url":null,"abstract":"The use of Digital Rights Management (DRM) technologies for the enforcement of digital media usage models is currently subject of a heated debate. Content creators, owners and distributors argue that DRM technologies are needed to protect their Intellectual Property (IP) from unauthorized access. A counter argument from the Information Technology (IT) and Consumer Electronics (CE) industries states that DRM technologies are obstacles to innovation. Academic institutions add to the discussion by claiming that DRM technologies and associated legislation interfere with their academic mission. Yet another point of view is provided by consumer organizations who claim that DRM technology interferes with basic personal rights, such as the right to make back-up copies for personal use. Finally, national governments express concern that the deployment of DRM technology violates open market rules and regulations and is associated with anti-competitive behavior. This last issue has lately gained increased attention in a number of European countries. In this talk we argue that a number of the concern listed above can be resolved by introducing a sufficiently powerful DRM interoperability framework. In particular we discuss the CORAL DRM interoperability framework that allows multiple DRM systems to seamlessly work together while at the same time requiring minimal modification to participating DRM systems. After introducing the problem of DRM interoperability the following topics will be addressed: (1) approaches to DRM interoperability, (2) introduction to the CORAL architecture, (3) building ecosystems on top of Coral, (4) integrating DRM systems into CORAL and (5) deploying CORAL. We end the talk by going back to the initial problem statement, summarizing to what extent CORAL resolves the identified issues and what work remains to be done.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133020033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional superdistribution citemori: superdistribution approaches do not address consumer privacy issues and also do not reliably prevent the malicious consumer from indiscriminately copying and redistributing the decryption keys or the decrypted content. The layered nature of common digital content can also be exploited to efficiently provide the consumer with choices over the quality of the content, allowing him/her to pay less for lower quality consumption and vice versa. This paper presents a system that superdistributes encrypted layered content and (1) allows the consumer to select a quality level at which to decrypt and consume the content; (2) prevents the merchant from knowing which exact content package is consumed by the consumer, hence enhancing consumer privacy; and (3) through trusted access control, prevents the consumer from indiscriminately copying and redistributing the decryption keys or the decrypted content, thus achieving a form of digital rights management.
{"title":"Privacy-enhanced superdistribution of layered content with trusted access control","authors":"Daniel J. T. Chong, R. Deng","doi":"10.1145/1179509.1179517","DOIUrl":"https://doi.org/10.1145/1179509.1179517","url":null,"abstract":"Traditional superdistribution citemori: superdistribution approaches do not address consumer privacy issues and also do not reliably prevent the malicious consumer from indiscriminately copying and redistributing the decryption keys or the decrypted content. The layered nature of common digital content can also be exploited to efficiently provide the consumer with choices over the quality of the content, allowing him/her to pay less for lower quality consumption and vice versa. This paper presents a system that superdistributes encrypted layered content and (1) allows the consumer to select a quality level at which to decrypt and consume the content; (2) prevents the merchant from knowing which exact content package is consumed by the consumer, hence enhancing consumer privacy; and (3) through trusted access control, prevents the consumer from indiscriminately copying and redistributing the decryption keys or the decrypted content, thus achieving a form of digital rights management.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130687682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trusted computing has received criticism from those who fear it will be used by influential market forces to exert power over the software used on consumer platforms. This paper describes an open architecture for digital rights management (DRM) enforcement on trusted computing platforms that empowers the consumer to select their operating-system and applications, including open-source options, without weakening the strength of the security functions. A key component in the architecture is a security manager that enforces mandatory access controls on shared devices, restricted information flows between virtual machines, and DRM policy on protected objects. The paper describes two use-cases: a DRM scenario with protected media content and remote home-working on sensitive medical data.
{"title":"Towards an open, trusted digital rights management platform","authors":"Andrew Cooper, Andrew P. Martin","doi":"10.1145/1179509.1179525","DOIUrl":"https://doi.org/10.1145/1179509.1179525","url":null,"abstract":"Trusted computing has received criticism from those who fear it will be used by influential market forces to exert power over the software used on consumer platforms. This paper describes an open architecture for digital rights management (DRM) enforcement on trusted computing platforms that empowers the consumer to select their operating-system and applications, including open-source options, without weakening the strength of the security functions. A key component in the architecture is a security manager that enforces mandatory access controls on shared devices, restricted information flows between virtual machines, and DRM policy on protected objects. The paper describes two use-cases: a DRM scenario with protected media content and remote home-working on sensitive medical data.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133208373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the most fundamental problems in computer security is protecting sensitive digital information from unauthorized disclosure. There are a number of challenges, such as spyware, removable media, and mobile devices, which make this a very hard problem. The problem becomes even more difficult when the adversary is somebody who is authorized to view the data. This is what is commonly referred to as an insider information leak. Insider leaks often occur out of malice, but sometimes are just due to plain negligence, as was the case with a recent leak of 26 million U.S. veterans' names, birth dates, and social security numbers. Current systems make an attempt to protect against this type of disclosure, but use rudimentary techniques that can be easily bypassed by a knowledgeable attacker. Examples include disabling "print" and "save" menu options within an application or scanning network traffic for signatures of known sensitive content. This paper examines a new method for protecting sensitive content from unauthorized disclosure, a View-Only File System (VOFS). VOFS relies on trusted computing primitives and virtual machine (VM) technology to provide a much greater level of security than current systems. In VOFS, a secure virtual machine on the client authenticates itself with a content provider and downloads sensitive data. Before allowing the user to view the data in his or her non-secure VM, the VOFS client disables non-essential device output. This prevents the user, or any malicious software, from printing, uploading, or stealing the sensitive content. When the user is done viewing a sensitive file, VOFS will reset the machine to previous state and resume normal device activity. Our goal is to provide near-seamless access to view-only files, while at the same time securing them from unauthorized digital replication. This paper presents the initial design, development plan, and evaluation plan for VOFS.
{"title":"Securing sensitive content in a view-only file system","authors":"Kevin Borders, Xin Zhao, A. Prakash","doi":"10.1145/1179509.1179515","DOIUrl":"https://doi.org/10.1145/1179509.1179515","url":null,"abstract":"One of the most fundamental problems in computer security is protecting sensitive digital information from unauthorized disclosure. There are a number of challenges, such as spyware, removable media, and mobile devices, which make this a very hard problem. The problem becomes even more difficult when the adversary is somebody who is authorized to view the data. This is what is commonly referred to as an insider information leak. Insider leaks often occur out of malice, but sometimes are just due to plain negligence, as was the case with a recent leak of 26 million U.S. veterans' names, birth dates, and social security numbers. Current systems make an attempt to protect against this type of disclosure, but use rudimentary techniques that can be easily bypassed by a knowledgeable attacker. Examples include disabling \"print\" and \"save\" menu options within an application or scanning network traffic for signatures of known sensitive content. This paper examines a new method for protecting sensitive content from unauthorized disclosure, a View-Only File System (VOFS). VOFS relies on trusted computing primitives and virtual machine (VM) technology to provide a much greater level of security than current systems. In VOFS, a secure virtual machine on the client authenticates itself with a content provider and downloads sensitive data. Before allowing the user to view the data in his or her non-secure VM, the VOFS client disables non-essential device output. This prevents the user, or any malicious software, from printing, uploading, or stealing the sensitive content. When the user is done viewing a sensitive file, VOFS will reset the machine to previous state and resume normal device activity. Our goal is to provide near-seamless access to view-only files, while at the same time securing them from unauthorized digital replication. This paper presents the initial design, development plan, and evaluation plan for VOFS.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132145342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bertrand Anckaert, Mariusz H. Jakubowski, R. Venkatesan
Despite huge efforts by software providers, software protection mechanisms are still broken on a regular basis. Due to the current distribution model, an attack against one copy of the software can be reused against any copy of the software. Diversity is an important tool to overcome this problem. It allows for renewable defenses in space, by giving every user a different copy, and renewable defenses in time when combined with tailored updates. This paper studies the possibilities and limitations of using virtualization to open a new set of opportunities to make diverse copies of a piece of software and to make individual copies more tamper-resistant. The performance impact is considerable and indicates that these techniques are best avoided in performance-critical parts of the code.
{"title":"Proteus: virtualization for diversified tamper-resistance","authors":"Bertrand Anckaert, Mariusz H. Jakubowski, R. Venkatesan","doi":"10.1145/1179509.1179521","DOIUrl":"https://doi.org/10.1145/1179509.1179521","url":null,"abstract":"Despite huge efforts by software providers, software protection mechanisms are still broken on a regular basis. Due to the current distribution model, an attack against one copy of the software can be reused against any copy of the software. Diversity is an important tool to overcome this problem. It allows for renewable defenses in space, by giving every user a different copy, and renewable defenses in time when combined with tailored updates. This paper studies the possibilities and limitations of using virtualization to open a new set of opportunities to make diverse copies of a piece of software and to make individual copies more tamper-resistant. The performance impact is considerable and indicates that these techniques are best avoided in performance-critical parts of the code.","PeriodicalId":124354,"journal":{"name":"ACM Digital Rights Management Workshop","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121041912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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