Direct comparison
Coretrustseal Vs Dsa: Key Differences & Comparison | CASRAI
The Data Seal of Approval (est. 2008) merged with WDS certification in 2017 to become CoreTrustSeal. DSA-certified repositories received CTS accreditation automatically.
Side-by-side comparison
| Dimension | Data Seal of Approval (DSA) | CoreTrustSeal (CTS) |
|---|---|---|
| Established | 2008, by DANS (Data Archiving and Networked Services), Netherlands | 2017, by merger of DSA and ICSI/WDS (World Data System) certification |
| Status | Retired 2017; merged into CoreTrustSeal. No new DSA certifications issued since 2017. | Active; internationally recognised; periodically revised (current version 2023–2025) |
| Governance | Governed by DANS and a Dutch-managed peer community board | Governed by the CoreTrustSeal Board, with international membership drawn from certified repositories and research data community organisations |
| Number of requirements | 16 requirements across background, data management, and infrastructure sections | 16 requirements (R0–R15) across background, organisational infrastructure, digital object management, technology, security, and ethics domains |
| Review process | Self-assessment with peer review from the DSA community; relatively lightweight process | Self-assessment with peer review by two external reviewers appointed by the CoreTrustSeal Board; more structured review procedure than DSA |
| International recognition | Widely adopted in Europe, particularly in the Netherlands, Germany, and the UK; less recognised outside Europe | Internationally recognised; referred to in EC open data policy, Horizon Europe guidelines, and the EOSC Rules of Participation |
| Relationship to ISO 16363 | Positioned as a lighter-weight community alternative to ISO 16363 third-party audit; the DSA was sometimes called the "entry-level" tier | Officially positioned as the mid-tier in a three-tier framework: informal guidelines → CoreTrustSeal community review → ISO 16363 third-party audit |
| Transition | All DSA-certified repositories were grandfathered into CoreTrustSeal accreditation in 2017 without a new application process | New applicants apply directly for CoreTrustSeal; DSA-era repositories must renew under CTS requirements at their renewal date |
Common questions
FAQ
Are DSA-certified and CoreTrustSeal-certified repositories the same?+
Functionally, yes — repositories that held DSA certification were grandfathered into CoreTrustSeal accreditation in 2017 without needing to reapply. However, DSA is now a retired standard and "DSA-certified" is outdated terminology. Repositories that were DSA-certified have subsequently been required to renew under CoreTrustSeal's current requirements at their renewal date. If a repository claims to be "DSA-certified" without also claiming CoreTrustSeal certification, that certification has likely expired and should not be treated as current.
How does CoreTrustSeal differ from ISO 16363?+
ISO 16363 (Audit and Certification of Trustworthy Digital Repositories) is a formal third-party audit standard based on the OAIS reference model (ISO 14721). It is conducted by accredited external auditors and requires deep documentation of every aspect of repository operations. ISO 16363 certification is expensive, time-consuming, and rare — only a small number of repositories worldwide hold it. CoreTrustSeal uses community peer review rather than external audit, is significantly cheaper and faster, and is far more widely adopted. The two exist in a complementary tiered framework: CoreTrustSeal provides broad community assurance; ISO 16363 provides the highest level of formal assurance for repositories with the largest regulatory or long-term preservation responsibilities.
Which certification do funders recognise?+
CoreTrustSeal is the most widely recognised repository certification in the research funding community. Horizon Europe guidelines and the EOSC Rules of Participation reference CoreTrustSeal as evidence of repository trustworthiness. UK funders including UKRI and Wellcome Trust do not mandate CoreTrustSeal specifically, but recommend deposition in "trustworthy repositories" and cite CoreTrustSeal certification as one indicator of trustworthiness. ISO 16363 is recognised as a higher-tier standard but is not generally required by funders given its rarity.
What are the TRUST principles and how do they relate to CoreTrustSeal?+
The TRUST principles — Transparency, Responsibility, User focus, Sustainability, and Technology — were articulated by Lin et al. in 2020 in Scientific Data (doi:10.1038/s41597-020-0486-7) as a conceptual framework for trusted data repositories. They were developed after CoreTrustSeal was established but map closely onto its requirements. TRUST provides a vocabulary for discussing what makes a repository trustworthy; CoreTrustSeal provides the operational certification process. Funders and authors often reference both together: TRUST for principles, CoreTrustSeal for evidence of compliance.
Going deeper
