Evaluation of Trust Service and Software Product Regimes for Zero-Knowledge Proof Development Under Eidas 2.0

Abstract

This paper examines two legal models for Zero-Knowledge Proof protocols in the context of the eIDAS 2.0 Regulation proposal: a trust service or a software product. The ARIES: reliAble euRopean Identity EcoSystem EU project highlighted the need for a legal framework for stakeholders to accept proof of existence of user data with legal certainty, while Hyperledger Indy shows that ZKP solutions are currently commercialized, stressing deficiencies in the eIDAS 2.0 proposal. An overview of ZKP applied to identity, its relationship to the European Digital Identity Wallet, the electronic attestations of attributes, both introduced by the eIDAS 2.0 proposal, and Self-Sovereign Identity systems, leads to the central question of proof of existence of user-held data as a trust service or as a software product. Our findings suggest that the path we take may lead us to the largest system of surveillance and control in electronic environments to date, or to an environment where instead of sharing data we share proof of its existence to achieve true decentralized identity systems in the EU environment.

Keywords: ZKP, eIDAS 2.0, EUDIW, Electronic attestation of attributes, SSI, Data privacy