A Blockchain-Based Chain of Custody for Digital Evidence: Design and Evaluation

Abstract

Maintaining a trustworthy chain of custody is essential to ensure the integrity, provenance, and admissibility of digital evidence. However, traditional evidence-management systems often suffer from opacity, limited auditability, and susceptibility to insider abuse or procedural errors. To address these gaps, we propose a blockchain-based chain-of-custody framework built on Hyperledger Fabric. In this design, the full lifecycle of evidence is logged as immutable, permissioned ledger entries, while artefacts themselves remain protected in secure off-chain repositories. Each event is captured through signed metadata and cryptographically time-stamped records, providing tamper-evident traceability. Custody workflows are encoded in Fabric chaincode, with role-based, multi-party authorization required for sensitive transitions. Moreover, Fabric’s privacy channels and fine-grained access controls enable cross-agency collaboration without unnecessary data exposure. A prototype implementation shows that the system achieves end-to-end accountability, practical throughput, and sub-second median latency on commodity hardware-demonstrating that stronger evidentiary assurance can be achieved for law-enforcement and forensic applications without incurring prohibitive operational costs.