Verifiable Credentials and the Digital Product Passport: building trust into DPP data

A Digital Product Passport is only as trustworthy as the claims inside it. Who says this jacket is 60% recycled polyester? Who guarantees this battery’s carbon figure? Verifiable Credentials answer that question with cryptography instead of trust-me. This guide explains what they are and why they are becoming a natural companion to the DPP.

The trust problem inside every passport

A passport aggregates claims from many sources: a mill, a lab, a manufacturer, a repairer. If those claims are just fields in a database, a reader has to trust whoever controls the database. That is fine inside one company and fragile across a whole value chain — exactly where the DPP is meant to operate.

What are Verifiable Credentials?

Verifiable Credentials (VCs) are a W3C standard for expressing claims in a tamper-evident, cryptographically signed form. The model has three roles: an issuer (say, an accredited lab) signs a claim; a holder (the product’s passport) carries it; and a verifier (a customer, customs, a marketplace) checks the signature. Crucially, the verifier can confirm the claim is authentic and unaltered without calling the issuer.

How VCs fit the DPP

Instead of a passport asserting “60% recycled” as plain text, it can carry a signed credential from the lab that measured it. The composition, the compliance certificate, the provenance attestation — each becomes an independently verifiable claim. The passport stops being a document you trust and becomes a bundle of proofs you can check.

• Composition & sustainability: lab-signed attestations of recycled content or substances.
• Compliance: conformity statements issued by the responsible party.
• Provenance: origin and chain-of-custody claims signed at each step.

Where VCs meet identity and events

VCs do not replace GS1 identity or EPCIS 2.0 events — they layer trust on top of them. Identity says which product; events say what happened; credentials say who vouches for it, provably. Research on DPP systems keeps surfacing the same requirement: Jansen and colleagues (2023) list data sovereignty and trust as core, and King and colleagues (2023) frame the passport as a multi-stakeholder ecosystem — both problems that verifiable, self-contained proofs are well suited to solve.

How to approach VCs without over-engineering

You do not need to credential everything on day one. Start with the highest-stakes claims — the ones a buyer, regulator or resale market actually questions — and issue those as verifiable credentials. Keep identity and events on open standards so credentials have something solid to attach to. This is emerging practice, not yet universal, and building on open standards keeps you ready as it matures.

Frequently asked questions

Are Verifiable Credentials required for a DPP?

Not today. The ESPR mandates a passport on open standards; VCs are an emerging way to make the claims inside it independently verifiable. Expect them to grow in importance as trust requirements tighten.

Do VCs need blockchain?

No. Verifiable Credentials are a W3C standard based on cryptographic signatures; they can use various trust anchors and do not require a blockchain.

What is the difference between a VC and a QR code?

The QR code links to the passport; a VC is a signed claim inside it that anyone can verify without trusting the platform that stores it.

References

• Jansen, M., Meisen, T., Plociennik, C., Berg, H., Pomp, A., & Windholz, W. (2023). Stop Guessing in the Dark: Identified Requirements for Digital Product Passport Systems. Systems, 11(3), 123. https://doi.org/10.3390/systems11030123
• King, M. R. N., Timms, P. D., & Mountney, S. (2023). A proposed universal definition of a Digital Product Passport Ecosystem (DPPE). Journal of Cleaner Production, 384, 135538. https://doi.org/10.1016/j.jclepro.2022.135538

Related reading: What is a Digital Product Passport? · GS1 EPCIS 2.0 explained · DPP-as-a-service