Blockchain-Based Evidence Tracking System for Forensic Integrity and Secure Chain of Custody

Securing forensic evidence integrity and security is fundamental to avoid tampering, loss, and illegal access. Classic centralized evidence management systems are easy to manipulate and breach. The current paper advocates for a blockchain-based forensic evidence management system that uses the Ethereum ERC-721 token standard to tokenize each bit of evidence as a non-fungible token (NFT) to promote immutable ownership and verifiable access.The system uses wallet-based authentication and role-based access control (RBAC) to limit evidence handling to authorized users. Key metadata, such as timestamps, digital hashes, and access logs, are recorded immutably on the blockchain. Smart contracts perform verification, logging, and auditing automatically, minimizing human errors and improving operational efficiency. A hybrid storage model stores ownership records on-chain while keeping large forensic files off-chain.