Certificate Verification in Dual Blockchain Model using Threshold Signature and Zero Knowledge Proofs

Abstract

Certificate authentication in online systems is required to ensure integrity and authenticity and prevent forgery. Traditional blockchain-based approaches work with double-chain architecture without any privacy-preservation capability or pack whole certificates into a single chain and incur substantial storage overhead. In this study, we introduce a light-weight dual-blockchain architecture with an external verification and audit side-chain and an inner chain for offline storing certificates. Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge (Zero Knowledge Proofs) are employed to sign hashes without revealing sensitive information, and threshold signatures are employed to sign certificates. Compared to the traditional single-chain and double-chain architecture, the proposed system realizes up to 30% lower latency and 25% higher throughput based on experimental results on 1,000–100,000 certificate dataset. These results indicate the efficiency, scalability, and privacy-preserving feature of the proposed solution, which can be applied to large-scale applications for certificate management.