Our app is a demo implementation of anonymous age proofs, using an BBS-based anonymous credentials in the commit-and-prove paradigm with Pedersen commitments, following the approach described in Vision: A Modular Framework for Anonymous Credential Systems and using ECDSA device binding. The range proof for the validity period is implemented using Bulletproofs++. Revocation is implemented using the signed-pairs approach (instantiated with BBS+ 23 and Bulletproofs++), as described in ePrint 2026/1824.
You can obtain the source code for our app here.
This work discusses how to modularize the cryptographic protocols for anonymous credentials, such that the standardized components can be used outside of the EUDI context, too. For the EUDI wallet context, a particular focus is on a modular solution for device binding of BBS credentials to legacy phones, that only support ECDSA-signatures.
Deployment of anonymous credentials in the EUDI Wallet is limited by smartphones' secure hardware that only supports legacy algoithms such as ECDSA, not the cryptography required by native device binding for anonymous credentials. We bridge this gap by proving possession of an ECDSA signature under a committed device key, enabling integration with modern anonymous credentials. We compare several approaches regarding implementation simplicity, standards compatibility, and efficiency.
We are a research group focused on cryptography and privacy-preserving technologies.