Digital Identity and the Interoperability Challenge

The quest for secure, scalable digital identity solutions is intensifying as governments and technology providers strive to create systems that work seamlessly across borders. Interoperability, or the ability for a system to work in multiple locations without modification, is emerging as a critical hurdle. Recent events, such as mobile driver's license (mDL) interoperability tests in Utrecht, The Netherlands, underscore this challenge, drawing parallels to the payment industry's evolution.

The Vision for Mobile Credentials

The ultimate goal of digital identity is the creation of universal digital wallets. These mobile-based repositories would allow individuals to present verifiable credentials on demand, whether online or offline. In this envisioned future, a student from Tokyo could easily use their mobile driver's license in a pharmacy in Berlin or a bar in Melbourne. To achieve this level of functionality, solutions are being developed according to the ISO 18013 series of standards. These standards extend beyond driver's licenses to include identity cards, health passes, and more under the broader concept of "mDocs".

Learning from Payments: Standards Plus Certification

The payment industry provides valuable lessons in achieving interoperability. The introduction of ISO 7816 in 1987 laid the groundwork for smartcards, but it was the EMV standards and certification programs that truly enabled global interoperability. Every card had to work at every terminal, every time. This reliability was not achieved by standards alone but through rigorous, system-wide testing against approved reference systems. Certification became the cornerstone of trust for issuers, acquirers, merchants, and consumers alike.

The Role of Testing in mDL Development

Interoperability tests, like those in Utrecht, are crucial for the development of mDLs. These tests brought together various global players, from wallet providers to system integrators, to validate their mDL implementations against the ISO 18013 framework. Companies such as Fime provided tools like the Digital Identity Test Suite to simulate both wallet and verifier roles. These were not theoretical exercises but involved real test transactions aimed at identifying gaps in standard implementation. These sessions represent the first steps towards a formal certification regime essential for ensuring mDLs are truly interoperable across borders and sectors.

The Question of Scheme Governance

Certification is necessary, but who will govern this process? In payments, global card networks like Visa and Mastercard naturally assumed this role. However, digital identity lacks a similar authority. In the EU, the revised eIDAS regulation assigns responsibility to member states, a model that may work regionally but could lead to fragmentation globally. Initiatives like the WE BUILD consortium, supported by the European Commission, aim to foster cohesion with interoperability as a key priority.

Conclusion

As digital identity solutions move towards mainstream adoption, achieving the same level of interoperability as payments will be crucial. The ability to replicate the payment industry's success in interoperability will likely determine which digital identity solutions endure and which ones fall by the wayside. The recent interoperability tests are a significant step forward, but establishing a robust governance scheme will be essential to ensure seamless functionality across borders and sectors.