Design and Functional Verification of a Blockchain-Based Hybrid Storage and Traceability System for Digital Certificates

Abstract

Digital certificates are widely used in employment screening, further education, professional qualification review, and cross-institutional information exchange. Centralized certificate management systems remain exposed to privileged modification, incomplete audit trails, inconsistent verification results, and unnecessary disclosure of holder attributes. This paper designs and functionally verifies a blockchain-based hybrid storage and traceability system for digital certificates. Certificate files and supporting materials are kept in an institutional off-chain repository, while the blockchain ledger records certificate identifiers, issuer information, cryptographic hashes, storage references, lifecycle states, timestamps, and transaction evidence. Hyperledger Fabric is adopted as the permissioned ledger layer, and chaincode governs issuance, verification, revocation, role-aware projection, and audit queries. The design stores compact verification evidence on-chain and keeps complete certificate attributes, record-specific salts, and certificate files under institutional authorization, thereby defining the confidentiality boundary of the shared ledger. A prototype implemented with Fabric v2.5, Gin, Vue.js, MySQL, and an off-chain repository verifies credential instantiation, on-chain anchoring, role-specific query, third-party masked verification, and traceability inspection. The verification results indicate an operational trust path for certificate authenticity, lifecycle auditability, and application-facing data minimization in institutional consortium settings.