A PRIVACY PRESERVING AND ACCOUNTABLE SELF-SOVEREIGN IDENTITY PROTOCOL

Abstract

Self-Sovereign Identity (SSI) has emerged as a result of the opposition and concern regarding the centralized control of user identities by third-party authorities. Although SSI successfully restores users' control over their own identities with the aid of blockchain, its viability has been called into question by privacy concerns arising from blockchain transparency as well as the lack of accountability measures like Know Your Customer (KYC) and Anti-Money Laundering (AML). In order to close this gap, we present AASSI, a groundbreaking SSI protocol that has been painstakingly created to strike a balance between the two requirements of accountability and privacy. In particular, AASSI offers support for selective revocation, selfderivation, fine-grained tracing, and anonymity. In order to improve privacy protection and self-management capabilities, AASSI presents redactable signatures, which enable users to independently generate unique credentials for every user service-provider contact. Regarding fine-grained tracing, the protocol uses a dual-tag approach that makes it easier to track down users' true identities and detailed history records of credentials that have been derived. AASSI uses dynamic accumulators as a building component for selective revocation, which allows problematic users to be revoked. Finally, we present a functional comparison that demonstrates the robustness of AASSI's features, namely its support for unique self-derived attributes that further enhance user control over their identification and fine-grained tracking that gives tracers greater freedom. Through an offchain time-consuming comparison, we illustrate the protocol's efficiency and show that AASSI significantly lowers the credential verification time overhead. Additionally, we demonstrate the viability of AASSI experimentally and test the on-chain communication overhead