by David Giaretta

...getting closer to an international system for audit and certification of the trustability of digital repositories.

The Preserving Digital Information report of the Task Force on Archiving of Digital Information (Garrett & Waters, 1996) declared, “A critical component of digital archiving infrastructure is the existence of a sufficient number of trusted organizations capable of storing, migrating, and providing access to digital collections”, and “A process of certification for digital archives is needed to create an overall climate of trust about the prospects of preserving digital information”. The issue of certification, and how to evaluate trust into the future (as opposed to a relatively temporary trust which may be more simply tested) is a request that has been repeated in many subsequent studies and workshops. The Open Archival Information System (OAIS) reference model provides many of the concepts on which such evaluations can be based.

Development of an ISO Accreditation and Certification process
The development of OAIS was hosted by the Consultative Committee for Space Data Systems (CCSDS) and approved by ISO as ISO 14721. OAIS contained a roadmap which listed a number of possible follow-on standards, some of which have already become ISO standards, after development within CCSDS.

The need for a standard for certification of archives was included in that list and the RLG/NARA work which produced TRAC (2007) was the first step in that process. The next step was to bring the output of the RLG/NARA Working Group back into CCSDS. This has now been done: the Digital Repository Audit and Certification (RAC) Working Group has been created, the CCSDS details are available from, and the working documents are available from Both are open to everybody. The openness of the development process is particularly important and the latter site contains the notes from the weekly virtual meetings as well as the live working version of the draft standards.

The first of the two basic standards, Audit and Certification of Trustworthy Digital Repositories (RAC, 2009), has been submitted to the standardization process and the second, Requirements for bodies providing Audit and Certification of Trusted Digital Repositories (drafts available on the RAC wiki) is near submission.

Besides developing the metrics, the Working Group has also been designing a strategy for creating the accreditation and certification process. In addition to the ‘central’ accreditation body there will be an eventual need for a network of local accreditation and certification bodies.

It has long been recognized that there is a need for a way to judge the extent to which an archive can be trusted to preserve digitally encoded information. On the one hand, funders of such archives need some formal certification process to provide assurance that their funding is well spent and that their important digital holdings will continue to be usable and understandable into the future. On the other hand it is probably also true that many who manage such archives would want some less formal process.

Considerable work has been carried out on the second of these aims, namely peer or informal certification. The RAC Working Group is close, at the time of writing, to taking important steps towards the first aim (formal ISO certification). Difficult organizational issues still need to be addressed but there is a clear roadmap for doing this. Even if all this is put in place, the take-up of the process and its impact on, for example, determining the funding of digital repositories is far from guaranteed. However in order to make progress, the RAC Working Group believes that the effort must be made.

Please contact:
David Giaretta
STFC, Rutherford Appleton Lab, UK
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Garrett, J. & Waters, D, (Eds). (1996). Preserving Digital Information, Report of the Task Force on Archiving of Digital Information commissioned by The Commission on Preservation and Access and The Research Libraries Group. Retrieved from:

National Science Foundation Cyberinfrastructure Council (NSF, 2007), Cyberinfrastructure Vision for 21st Century Discovery:

Open Archival Information System (OAIS) – Reference Model, ISO 14721:2003, (2003):

RLG-OCLC, (2002), Report on Trusted Digital Repositories: Attributes and Responsibilities:

TRAC, (2007), Trustworthy Repositories Audit & Certification: Criteria and Checklist:

RAC wiki:

RAC, (2009) Audit and Certification of Trustworthy Digital Repositories:


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