Renato Iannella, Susanne Guth - 3 June 2004
Overview of the Program
Rigo Wenning, W3C - "DRM and the Web"
Rigo Wenning is working for the W3C as a lawyer in the position of the privacy activity lead & policy analyst. He joined W3C in October 1999 with a focus on privacy and digital signatures. He is also in charge of contact to the European Commission and to European development initiatives.Rigo Wenning started his keynote talk with the general expectations of the DRM business. Close to the position of Lawrence Lessig ("The future of ideas") he stated that successful DRM systems have to position themselves "in the middle", i.e. between the aim of building total control for intellectual property rights with the help of commercial DRM systems and the aim of sharing all digital resources for free to allow new creative work. With respect to rights languages, ODRL could be positioned "in the middle" - between XrML and the Creative Commons. Rigo points out that ODRL needs more exact semantics. Profiles could help for this purpose. In profiles the ODRL initiative would give guidelines and examples on how ODRL can be (integrated and) applied by other (metadata) initiatives. For example, the ODRL initiative should publish a profile that shows the integration of ODRL rights expressions into the Web Services Definition Language (WSDL). As web services will become an important web technology, Rigo states that DRM should integrate into the Web Services Model. As soon as ODRL rights expressions are issued, which state rights of parties over assets, privacy issues come into play. DRM systems might be able to deal with this issue by plugging in P3P. Again, a profile for the integration of P3P into ODRL rights expressions becomes desirable.
Andreas Deppe, T-Systems Nova GmbH, "The OPERA Project: Interoperability of Digital Rights Management"
Andreas Deppe works for T-Systems Nova GmbH and is involved with DRM solutions and the OPERA project.
The main subject of Andreas Deppe's keynote talk was the OPERA project that addresses interoperability between various DRM systems and their components. The OPERA project has the objective to specify an open DRM architecture that addresses the needs of all three groups: content providers, DRM system operators, and customers. With respect to rights languages, the OPERA project is using a proprietary rights language. Deppe arguments this design decision with the uncertainty of the REL standards movement, i.e., for OPERA it was not clear which of the current REL standards would prevail. The OPERA project aims at supporting interoperability by issuing licenses that are independent of the DRM system and that are independent of the rendering device. The OPERA project started with the support of a small set of simple business models. More sophisticated ones are planned for a later phase of the project. Deppe stated that DRM systems are not just of interest for the business to consumer market, but also for the business to business market, i.e. for the entire value chain of electronic goods. Finally, Andreas Deppe shared the experience that content providers and service providers currently show a high interest in investing and running interoperable DRM systems.
Willms Buhse, CoreMedia - "OMA Secure Content Delivery for the Mobile World"
Willms Buhse is head of products and marketing and executive board member of the CoreMedia AG in Hamburg Germany. He is also Vice Chair of the OMA Download and DRM working group.
The workshop chairs have invited a representative of the Open Mobile Alliance (OMA) for a keynote talk, as the OMA is an important standards body for the mobile domain and has accepted ODRL as standard rights expression language in its framework. Willms Buhse started his talk with a short introduction of the OMA that has about 370 members and a DRM working group of approximately 50 participants. Willms Buhse states that currently more mobile devices support OMA DRM than the DRM solution of Microsoft. The large acceptance of OMA means at the same time a large acceptance and implementation of ODRL in mobile devices. The OMA standard, version 1.0 which is implemented in the current new phones allow for a "light" DRM, i.e. the implementation of limited DRM functions for low value content. In April 2004 the OMA has completed the OMA standard version 2.0 which provides rights management for high value premium content and includes more sophisticated DRM features as well as improved provisions for security. Buhse stressed that superdistribution of content will play an important role for the mobile domain. Therefore, open standards, i.e. the implementation of OMA standards, are required to enable the distribution between all kinds of different device and service types. The OMA enables the "fair use" of mobile content by supporting user defined domains in which content can be exchanged across devices. He stressed that implementing "fair use" features and interoperability between various DRM devices are vital.
In this report we only briefly address the main statements of the papers and their relevance for ODRL and its further development. For complete papers (and presentations), please refer to the ODRL Workshop webpage.
Ivana Dusparic presented the paper "A pervasive application rights management architecture based on ODRL". This work is focused on occasionally connected mobile devices exchanging electronic goods and services. As the OMA standard is leading in the mobile domain, ODRL was used for the prototype implementation. Actually, the authors chose a subset of ODRL, using simply the right "execute". The standard vocabulary of ODRL was not sufficient as it does not define rights for functions of software. Therefore, the permission data dictionary was extended. Ivana stated that there was a need to express duties for all contracting parties and that this feature is currently not provided by ODRL. (Please refer to the talk of Susanne Guth for a discussion of duties).
Jaime Delgado presented the paper "Interoperability between ODRL and MPEG-21 REL". He showed an approach how to directly map XrML, respectively MPEG-21 REL to ODRL with the help of XSLT. The audience discussed this approach controversially, as it was lacking a generic information model that mediates between the two languages. Rigo Wenning stated that an approach for the translation from one language to the other requires a mapping of both rights languages to a generic RDF model and then develop an Ontology for it.
Oyvind Vestavik presented the paper "REAP: A System for Rights Management in Digital Libraries". To meet all requirements of the prototype implementation - using the Alexandria Digital Library project - he used an ODRL subset and extended the context element with a specialized library identification field.
Susanne Guth presented the paper "A proposal for the Evolution of the ODRL Information Model". She stated that the current data model of ODRL has some shortcomings, for example, currently rights and duties can only be expressed for the customer but not for the rightsholder, no constraints can be specified for requirements (such as payment within two weeks), etc. Based on the listed shortcomings a new data model was proposed that would enrich the expressiveness of ODRL and eliminate the shortcomings of ODRL. The change of the data model is not an extension of ODRL but a realignment for clear semantics. The paper includes revised XML schemas for the ODRL expression language as well as for the ODRL data dictionary.
Stephen Downes presented the paper "Distributed Digital Rights Management: The EduSource Approach to DRM". Apart from presenting the concept of a "purchaser broker". He was motivating the integration of ODRL into LOM descriptions for learning objects. The rights element of the LOM metadata would link to an extra ODRL document that expresses a certain set of rights. Thus, ODRL rights expressions could be reused by a large number of learning resources. Finally, Stephen argued that there is no "one" DRM system architecture, but different DRM systems for different markets.
Stefan Katzenbeisser presented the paper "Towards Formal Semantics for ODRL". Stefan demonstrated how the formal semantics of ODRL rights expressions can be expressed as automata. Each ODRL rights expression can have different formal semantics. Thus, future ODRL versions should include template automata for each rights expression element that can be combined. Difficulties arise with the automata notation when expressing lend and time-based constraints. Eckhart Koeppen from Nokia commented that for software engineers such formal semantics are very important as formal semantics can be translated to state machines and immensely reduce the risk of misinterpreting licenses.
Olli Pitkanen presented the paper "Nonius: Implementing a DRM Extension to an XML Browser". His team implemented a subset of ODRL in an XML-based browser. They found that ODRL was well written and easy to understand, but implementing some of the enforcement actions, XML lining, and boolean operations was challenging.
Stephane van Hardeveld presented the talk "Flexible DRM: Real-Life ODRL Implementations". The company VirtuosoMedia in the Netherlands is running several commercial DRM platforms for audio and video content. The company recognized the need for open standards and interoperability. Their DRM solutions are based on ODRL. For the implementations, a subset of ODRL has been used. The customer can choose between some predefined, enforceable contracts formulated in ODRL.
Mariemma Yague presented "An Interoperable and Flexible Infrastructure for DRM". She presented the approach of "semantic access control", i.e. access control that is based on the semantics of the resource and its context. She stressed the need for a general framework capable of supporting very heterogeneous DRM applications and scenarios.
The final afternoon of the workshop was dedicated to looking at the path forward for the ODRL Initiative. The workshop delegates discussed four key areas for future development.
1 - WHY
This area focussed on the high level principles of the ODRL Language that can be used as a fundamental guide for the overall direction and it's objectives. Some of the major outcomes included:
2 - SCOPE
This area focussed on the scope of future versions of the ODRL Language. Some of the major outcomes included:
In addition to what may be in scope for ODRL, a number of features of the current version may be removed as they are provided by other standards/systems or have been found to be used infrequently and may overload the language's implementability. Some of these may include, the revoke function, digital signatures and encryption, and entity sequencing.
3 - WHAT
This area focussed on some of the new features of future versions of the ODRL Language. Some of the major outcomes included:
In addition, a number of separate documents were envisaged for version 2.0 of ODRL:
4 - PROCESS
This area focussed on the processes and governance of the ODRL Initiative. Some of the major outcomes included:
The Workshop was clearly a major success and provided the timely and necessary forum for ODRL researchers and implementors to share experiences and new ideas.
The key next steps are to develop a work plan for the technical development of the next version of ODRL and to establish the ODRL International Advisory Board to manage the goverance processes for the Initiative.
For general questions about the ODRL International Workshop please send email to workshopodrl.net
Last Updated on 2004-06-03