BLOCKCHAIN-BASED CHAIN-OF-CUSTODY MODELS FOR TAMPER-PROOF EVIDENCE PRESERVATION IN DIGITAL FORENSICS INVESTIGATIONS

Abstract

In the evolving landscape of cybercrime and digital investigations, the integrity and traceability of digital evidence are paramount.Traditional chain-of-custody (CoC) mechanisms in digital forensics rely heavily on centralized systems, manual logging, and institutional trust, all of which are prone to human error, tampering, and data loss.This study introduces a blockchain-based chain-of-custody model aimed at ensuring immutable, transparent, and verifiable tracking of digital evidence across its entire lifecycle-from acquisition and analysis to presentation in court.Leveraging blockchain's decentralized architecture and cryptographic immutability, the proposed framework records every interaction with digital evidence, including transfers, access logs, and analysis events, in a tamper-proof ledger distributed across trusted nodes in a forensic network.Smart contracts automate procedural compliance, access permissions, and time-stamping, thereby reducing reliance on third-party oversight and enhancing procedural integrity.The system was designed and simulated using Hyperledger Fabric, integrating role-based access control and hash-based evidence fingerprinting.Benchmark testing demonstrated the model's robustness in preserving forensic timelines under various adversarial scenarios, including internal breaches and unauthorized access attempts.In addition to enhancing evidentiary credibility, this blockchain-enhanced CoC model offers interoperability with existing digital forensic tools and forensic readiness systems.By aligning with legal admissibility standards and ensuring end-to-end accountability, the framework strengthens the evidentiary chain, particularly in multi-jurisdictional and cloudbased investigations.As digital forensics faces increasing scrutiny regarding evidentiary handling, this research presents a scalable and future-proof alternative to conventional CoC practices-crucial for maintaining the rule of law in cybercrime prosecutions.