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CNRI's program of research and development in digital libraries has a number of inter-related activities that overlap and build upon each other. The work includes development of core technology that is used in several testbeds and implementation projects, with funding from a variety of sources.

The Digital Object Architecture Project continues the architectural work of the DARPA-funded Computer Science Technical Reports Project (CSTR).

The project focuses on the development of an infrastructure of services that provide access to distributed and secure digital objects. Digital objects are networked objects that are instantiated by an infrastructure service we call a repository. Digital objects provide access to their content using an extensible and secure dissemination mechanism. Disseminations can be thought of as high level types that are uniquely distinguished by a combination of operations, and types of data the latter are performed on. Disseminations consist of mobile code called Servlet that can be designed, implemented, and registered with the digital object infrastructure by anyone with the proper permissions. Any digital object with the appropriate rights can automatically use registered servlets. This extensible dissemination mechanism enables digital objects to accommodate a wide variety of possible content, from complex to simple, static or dynamic, and from permanent to real time data. Disseminations have few operational limits and enable digital objects to dynamically generate or acquire their content.

Current ongoing research includes the development of dissemination registry, infrastructure searching, security and scalability.

Support for the Digital Object Architecture project is provided by DARPA, the Library of Congress, and the Defense Technical Information Center (DTIC), through DARPA grant MDA972-92-J-1029.


Figure 1

Figure 1 shows the principal system components. CNRI's research concentrates on the concept of digital objects, the Handle System for identifying digital objects, and the Repository for storing them and making them available over the Internet. The Registry is a specialized repository that is used to authenticate digital objects.

The Handle System is a system for providing persistent names for Internet resources. It is a highly reliable, high performance, distributed system.
The Repository Provides network based storage and access to digital objects. All access to digital objects passes uses a simple repository access protocol and is subject to access controls established by the manager of the repository.
The Registry is a specialized repository that provides secure registration and authentication of digital objects.

Applications, Testbeds, and Partners

U. S. Copyright Office (CORDS). This system provides copyright registration and deposit of digital materials over the Internet. When completed, it will integrate the Registry, Handle System, and Repository with the production systems at the Library of Congress.
Defense Virtual Library. CNRI is working in partnership with the Defense Technical Information Center (DTIC) to design and development a digital library for DTIC's extensive collection of report literature.













  • Sam X. Sun, "Internationalization of the Handle System - A Persistent Global Name Service". A paper presented at the 12th International Unicode Conference in Tokyo in April 1998.
  • This paper is available in Adobe PostScriptÆ format to ensure proper rendering of non-ASCII characters.






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Updated: 21 Sep 01