Paper 2026/1723

De-SyRIS: A Decentralized Sybil-Resistant Identity System without a Trusted Credential Issuer

Abstract

While decentralized identity management systems strive for autonomy, most still rely on centralized mechanisms (e.g., phone numbers or government-issued IDs) to achieve Sybil resistance and prevent fake identity attacks. This article proposes an identity management architecture that ensures robust Sybil resistance and is fully decentralized, unlike the systems currently in widespread use. The proposed solution synergizes facial biometric verification with anti-Sybil social graph analysis. By leveraging blockchain technology, zero-knowledge proofs, and trusted execution environments, the system ensures the uniqueness, anonymity, and privacy of registered users without relying on centralized authorities. The operation of the proposed system was demonstrated through simulations of a network of 100 entities across three social graph models and through a proof-of-concept implementation that utilizes fast Plonky2 zero-knowledge proofs. To our knowledge, this is the first work that proposes a Sybil-resistant identity system without sacrificing decentralization and privacy, while not relying on any centralized credential issuers.