EUDI Guide: Build a Secure EUDI Wallet Relying Party

Are you a EUDI Relying Party? eIDAS 2.0 brings statutory security obligations. Learn to protect your RP app from cloning, malware, and mobile fraud.

The digital identity landscape in Europe is undergoing its most significant shift in a decade. With the entry into force of Regulation (EU) 2024/1183 (eIDAS 2.0), every EU Member State is now mandated to offer at least one European Digital Identity Wallet (EUDIW) to its citizens. From the moment those wallets go live, any app or website that wants to accept identity attributes from them automatically becomes a Relying Party (RP) under the EUDI Architecture Reference Framework (ARF).

This article serves as the essential starting point for a comprehensive, multi-part series designed specifically to help CTOs, architects, and mobile developers secure the entire EUDI Relying Party infrastructure.

Here, in Article 1, we will break down the regulatory changes and expose the mobile threat surface nobody warned you about — the blind spot the specifications don’t cover, making runtime device security entirely your problem to solve.

This multi-part series is built for CTOs, architects, and mobile developers. We break down the regulatory clock, the architectural shifts, and the hands-on implementation details required to close the mobile security gap.

Explore the complete series:

• Part 1: Build a Secure EUDI Wallet Relying Party An overview of the new eIDAS 2.0 landscape, the mobile threat surface nobody warned you about, and how to map regulatory obligations to your security stack.
• Part 2: EUDI Wallet Integration: A CTO’s Decision Guide A strategic roadmap covering implementation timelines, the shift from real-time IdP callbacks to offline verification, and the privacy requirements your DPO needs you to know.
• Part 3: Secure EUDI Wallet Integration for Mobile Developers A hands-on implementation guide for securing the OpenID4VP flow, writing GDPR-compliant DCQL queries, and setting up robust backend verification gates.
• Part 4: App Attestation for EUDI Relying Parties A deep dive into platform attestation: AppiCrypt, Google Play Integrity and Apple App Attest , and how to build a resilient, cross-platform attestation strategy.

Disclaimer for full transparency: This article utilizes Talsec technology. We know we aren’t the only vendor in the mobile security space. But we are the one running on 2,000,000,000 devices. We’ve protected more apps than there are cars on Earth. It’s safe to say we know what we’re doing.​

What’s actually changing

Regulation (EU) 2024/1183, the revised eIDAS (eIDAS 2.0), entered in force on 20 May 2024. Every EU Member State must offer at least one European Digital Identity Wallet (EUDIW) to its citizens. From the moment a national wallet goes live, any app or website that wants to accept identity attributes from it becomes a Relying Party (RP) under the EUDI Architecture Reference Framework (ARF).

If your app:

• Onboards customers (KYC),
• Gates content by age, residence, profession, or qualification,
• Signs contracts or accepts qualified electronic signatures,
• Replaces username/password with wallet-based login,

…then you are a Relying Party. And RPs carry statutory security obligations.

The mobile threat surface nobody warned you about

EUDIW presentations happen on a smartphone. That smartphone is also where:

• The user’s wallet app lives (and can be cloned, repackaged, or shimmed).
• Your RP app lives (and can be reverse-engineered, hooked with Frida, and run on an emulator).
• Malware can read screens, intercept NFC signals, or screen-share to a remote operator.
• Social engineering can drive a real user to present credentials to a fake RP.

The eIDAS 2.0 implementing acts and the ARF push hard on the wallet side assurance. But the RP side is just as exposed, and largely your problem to solve.

What Talsec offers you

• Prove your RP app is genuine and untampered before accepting a presentation with ​**AppiCrypt®, **cross-platform app attestation
• Detect rooted/jailbroken devices, debuggers, hooking frameworks, emulators with ​RASP+ ​
• Detect known malware on the device interacting with your app with Malware Detection ​
• Detect screen overlays, accessibility abuse, and screen mirroring during a presentation with RASP+
• Bind the user, the device, and your RP app cryptographically with UserDevice Binding
• Defend against social-engineering / remote-control attacks during the OpenID4VP flow with RASP+

Proceed to the next article in this series, “EUDI Wallet Integration: A CTO’s Decision Guide,” to establish your strategic roadmap and understand the critical architectural shifts needed to ship securely.

written by Majid Hajian