Paper 2024/1348 Original: eprint.iacr.org/2024/1348 ↗

Zero-Knowledge Validation for an Offline Electronic Document Wallet using Bulletproofs

Abstract

We describe designs for an electronic wallet, meant for the housing of official government documents, which solves the problem of displaying document data to untrusted parties (e.g., in order to allow users to prove that they are above the drinking age). The wallet attains this goal by employing Zero-Knowledge Proof technologies, ascertaining that nothing beyond the intended information is ever shared. In order to be practically applicable, the wallet has to meet many additional constraints, such as to be usable in offline scenarios, to employ only widely-accessible communication methods which, themselves, must not impinge on the user’s privacy, and to be constructed solely over standard, widely-studied cryptographic algorithms, offering appropriately high levels of cryptographic security. We explain how our design was able to successfully meet all such additional constraints.