ChainSEAL: A Blockchain-based Secure and Adaptive Evidence Ledger

Abstract

Evidence management comes with requirements of a visibly secure, immutable, and scalable system to drive legal proceedings with ethicacy. Where research on fully on-chain solutions shows unrealistic and extravagant costs and performance limits, the traditional off-chain centralized storage systems exhibit an insecure environment, poor traceability, and tampering concerns. ChainSEAL is a hybrid Blockchain - IPFS-based forensic Evidence Management platform that integrates IPFS for encrypted Evidence file storage, blockchain as a distributed ledger for File hash and metadata, while off-chain storage for key management. The methodology explains the system flow, that as the evidence is submitted, the FIR is generated, the case request is created, and the evidence cycle is initiated. The cycle starts with fetching the SHA-256 of the file, then encrypting the evidence, submitting it on IPFS, fetching the Content Identifier (CID) of the file on IPFS, uploading the CID + File Hash + Metadata on-chain with a maintained verifiable Chain of Custody of the Evidence cycle. This ensures confidentiality and immutability of the system. The proposed framework is empirically evaluated for cost, storage efficiency, latency, and tamper-proofness. Its legal admissibility is established through an analysis of immutability, chain of custody integrity, and role-based access control.