Citadel: Self-Sovereign Identities on Dusk Network

TL;DR

This paper introduces Citadel, a privacy-preserving Self-Sovereign Identity system on Dusk Network that enables users to privately manage and prove ownership of digital identities and rights without revealing sensitive information.

Contribution

The paper presents a novel full-privacy-preserving SSI system using a native privacy-preserving NFT model on Dusk Network, enhancing user privacy in identity management.

Findings

Designed a native privacy-preserving NFT model for Dusk Network

Developed Citadel, a full-privacy SSI system with private rights storage

Enables private proof of ownership without revealing identity information

Abstract

The amount of sensitive information that service providers handle about their users has become a concerning fact in many use cases, where users have no other option but to trust that those companies will not misuse their personal information. To solve that, Self-Sovereign Identity (SSI) systems have become a hot topic of research in recent years: SSI systems allow users to manage their identities transparently. Recent solutions represent the rights of users to use services as Non-Fungible Tokens (NFTs) stored on Blockchains, and users prove possession of these rights using Zero-Knowledge Proofs (ZKPs). However, even when ZKPs do not leak any information about the rights, the NFTs are stored as public values linked to known accounts, and thus, they can be traced. In this paper, we design a native privacy-preserving NFT model for the Dusk Network Blockchain, and on top of it, we deploy Citadel: our novel full-privacy-preserving SSI system, where the rights of the users are privately stored on the Dusk Network Blockchain, and users can prove their ownership in a fully private manner.