Trusted Digital Repositories

In recent years, there have been multiple efforts to assess repositiories with the objective of making repository practices and procedures transparent, and assuring that valuable digital assets are protected.


CoreTrustSeal Data Repository certification is one such assessment initiative. It is meant to demonstrate to researchers that data repositories are taking appropriate measures to ensure sustainable and trustworthy data infrastructures. CoreTrustSeal is a legal entity under Dutch law governed by a Standards and Certification Board composed of 12 elected members representing the Assembly of Reviewers.

The CoreTrustSeal certification sets forth 16 guidelines related to trustworthy data management and stewardship. Core certification does not involve a site visit, although self-assessments are submitted for external review and should be supported by links to public evidence. Repositories are required to be reassessed every three years.

CoreTrustSeal replaces the Data Seal of Approval (DSA) certification and World Data System (WDS) Regular Members certification. ICPSR was one of the first six data repositories to earn the Data Seal of Approval in 2011. You can read ICPSR's 2011 and 2014 self-assessments. ICPSR earned the World Data System certification in 2013.

In Europe, the Consortium of European Social Science Data Archives (CESSDA) supports and provides training to all CESSDA service providers in acquiring and prolonging CoreTrustSeal certification.

Trusted Repositories Audit and Certification

A product of more than three years' work, Trusted Repositories Audit & Certification (TRAC) has its roots in a joint task force created to develop criteria enabling the identification of digital repositories capable of reliably storing, migrating, and providing access to digital collections. Originally sponsored by RLG (Research Library Group, now known as OCLC) and the US National Archives and Records Administration, the work grew to incorporate and leverage work from several organizations, laying the groundwork for international collaboration on digital repository audit and certification between the DCC, RLG, NARA, nestor, and the US Center for Research Libraries.

TRAC provides tools for the audit, assessment, and potential certification of digital repositories, establishes the documentation requirements required for audit, delineates a process for certification, and establishes appropriate methodologies for determining the soundness and sustainability of digital repositories.

Trusted Repositories Audit & Certification: Criteria and Checklist (PDF) incorporates the sum of knowledge and experience, new ideas, techniques, and tools that resulted from cross-fertilization between the U.S. and European efforts.

In 2006, ICPSR participated in an test audit of the TRAC checklist and procedures. Findings are available here --

ICPSR also makes available extensive information about its archival procedures in a section of this website titled ICPSR: A Case Study.

In March 2012, the TRAC standard was approved by the International Standards Organization (ISO) for publication.


The DRAMBORA initiative, developed by the The Digital Curation Centre (DCC) and DigitalPreservationEurope (DPE), provides a Digital Repository Audit Method Based on Risk Assessment (DRAMBORA) toolkit. This toolkit is intended to facilitate internal audit by providing repository administrators with a means to assess their capabilities, identify their weaknesses, and recognize their strengths.