6. Trusted repositories: bit preservation and document rendering

The OAIS reference model building block "Archival Storage" is responsible for keeping intact the bitstream of the digital object's preservation master. It may either be the original bitstream or the result of one of several migration procedures in the archive life cycle of the digital object.

Whatever strategy will be followed in the future to provide access to the digital content, it will depend on the existence of a bitstream, the integrity and authenticity of which has been kept in order over the years. It needs more than a RAID-5 disk storage system with redundant backup to guarantee this. Again, an OCLC/RLG working group has done groundbreaking work. The report "Attributes of a Trusted Digital Repository"^<13> has articulated a framework of attributes and responsibilities for trusted, reliable and sustainable digital repositories. As bit preservation strategies are well known and well tested in applied information technology, the challenge is rather organisational than technical. The report proposes to use and to formalize certification procedures as a means for proving reliability and trustworthiness of repositories over time. Networked repository services depend on cooperation. Transparency of workflows, definition of service levels and documentation of security provisions is a sound foundation for mutual trust.

On the basis of the preserved bitstream, document rendering will have to be enabled for future access to digital objects. Several strategies are in discussion and a lot of projects are prototyping various technical methods: from migration on request to the concept of a Universal Virtual Computer (UVC)^<14> . We assess them all as valuable efforts in order to achieve persistence for digital publications including ETDs.

Our hosts from Humboldt University do important work at the start of the production chain: they invest in promotion of authoring tools and end user services which should provide for well structured and preservation friendly ETDs using SGML/XML formats^<15> . All of us presenting papers at this conference have experienced that you need to tolerate and to adhere to a structured framework in order to profit from its advantages.

Our colleagues from the Royal Libray of the Netherlands in The Hague have inaugurated the first large scale implementation of a Digital Information Archiving System^<16> . Time is too short to list all the important efforts in Australia, the US and Europe, but you may use "PADI - the Subject Gateway to Digital Preservation Resources"^<17> for further information on this topic.

Synergies and possibilities for cooperation will have to be exploited to a maximum extent in order to be able to solve our future problems. It has been a good start using ETDs.

Footnotes:
<13>	http://www.rlg.org/longterm/repositories.pdf
<14>	http://www.kb.nl/kb/ict/dea/ltp/reports/4-uvc.pdf
<15>	http://www.edoc.hu-berlin.de/index_en.php
<16>	http://www-5.ibm.com/nl/dias
<17>	http://www.nla.gov.au/padi/

© This publication and its compilation in form and content is copyrighted. Every realization which is not explicitly allowed by copyright law requires a written agreement. Especially, this holds for reprography and processing / storing by electronic systems.