Secure Crypto Payments with the EUDI Wallet

Last update: March 2026

Introduction

The rapid growth of digital assets, stablecoins, and decentralized finance is transforming payments and digital commerce. However, the adoption of these technologies in Europe requires solutions that combine:

• regulatory compliance
• user privacy
• secure identity verification
• interoperability with EU digital identity frameworks

This repository provides a reference architecture and specification for enabling secure crypto and stablecoin payments using the European Digital Identity Wallet (EUDI Wallet).

The approach combines:

• Self-custodial crypto wallets
• Verifiable Credentials (VCs)
• OIDC4VP / OIDC4VCI protocols
• Selective disclosure with SD-JWT
• Strong Customer Authentication (SCA) aligned with the EUDI ARF TS12 specifications

The goal is to demonstrate how identity-assured crypto payments can be performed while preserving the decentralized nature of blockchain transactions.

For further background and industry insights, see the article: The Future of Compliant Crypto in Europe – EUDI Wallets and Stablecoin Transfers.

Specification Documents

• Crypto and Stablecoin Transfers secured with EUDI Compliant Wallet – Full technical specification.

Main Use Case

Secure Crypto Person-to-Merchant Payments (P2M)

The main use case described in this repository demonstrates how a natural person can pay a merchant using a non-custodial crypto wallet, while the EUDI Wallet provides the trusted identity and authentication layer.

In this architecture:

• the EUDI Wallet performs identity authentication and Strong Customer Authentication (SCA)
• the crypto wallet performs the blockchain transaction
• the payment gateway verifies the payment and the identity proof
• no intermediary executes the on-chain transaction

This separation allows the system to combine:

• self-custodial blockchain payments
• EU-compliant identity authentication
• privacy-preserving disclosure

Key Concepts

EUDI Wallet as Identity Layer

The EUDI Wallet acts as the trusted identity and consent layer for crypto payments.

It enables users to:

• authenticate using PID or other identity credentials
• present Proof of Crypto Account Ownership credentials
• sign transaction consent using advanced electronic signatures
• provide selective disclosure of identity attributes

Proof of Crypto Account Ownership (SCA Credential)

Strong Customer Authentication is implemented through a Proof of Crypto Account Ownership credential, issued as a Qualified Electronic Attestation of Attributes (QEAA) by a QTSP.

This credential proves that the user controls a specific blockchain account without exposing private keys.

Example claims include:

• blockchain network
• chain identifier
• blockchain account address

The credential is used during the OpenID4VP authentication flow to satisfy the SCA requirements defined in ARF TS12.

Decentralized Payment Execution

The blockchain transaction is executed directly by the user using their non-custodial crypto wallet.

Key properties:

• no custody by the payment gateway
• no intermediary executes the blockchain transaction
• the blockchain is used purely as a settlement layer

The payment gateway verifies the payment by:

1. receiving the authenticated payment request
2. monitoring the blockchain
3. matching the executed transaction using the shared transaction_id

Standards and Protocols

The architecture relies on open standards and EU frameworks including:

Identity and Wallet Standards

• EUDI Wallet ARF
• OpenID4VP
• OpenID4VCI
• SD-JWT VC

Payment Authentication

• ARF TS12 – Strong Customer Authentication

TS12 relies on VC Type Metadata to render transaction data in the wallet UI. Implementations should therefore support retrieving VC metadata from the vct URL, as wallet rendering may depend on the latest version of the metadata definition.

Blockchain Standards

• CAIP-2 chain identifiers
• EVM compatible chains
• Tezos
• other compatible DLTs

Regulatory Alignment

The specification is designed to align with European regulatory frameworks including:

eIDAS 2.0

• EUDI Wallet identity authentication
• Qualified Electronic Attestations of Attributes (QEAA)
• advanced electronic signatures

MiCA

• identity-assured crypto payments
• compliant merchant acceptance of crypto assets

TFR (Travel Rule)

• selective disclosure of originator information
• risk-based compliance

GDPR

• privacy by design
• no personal data written on-chain
• selective disclosure of attributes

Future Extensions

The architecture will continue evolving with support for:

• EVM wallets
• additional blockchain networks
• Digital Euro integration
• expanded merchant credential frameworks

License

This repository provides a reference specification and implementation guidance for research and interoperability purposes.

Please refer to individual document headers for detailed licensing information.