Blockchain Based Digital Evidence Protection System

Abstract

Digital evidence plays a crucial role in modern cybercrime investigation and judicial procedures. However, traditional evidence storage systems rely on centralized databases that are vulnerable to tampering, unauthorized modification, and data loss. Any alteration in stored evidence can invalidate its legal admissibility in court. Therefore, maintaining integrity, authenticity, and traceability of evidence is a major challenge.
This research proposes a blockchain-based evidence protection system implemented using a Python-based custom blockchain architecture. Instead of storing files directly inside the chain, the system generates a unique SHA-256 hash for each uploaded evidence file. The generated hash is stored in blocks that are cryptographically linked to previous blocks, forming an immutable chain. Even a single-bit modification in evidence results in a completely different hash value, enabling immediate tamper detection.
The system ensures integrity verification, chain of custody tracking, and non-repudiation without depending on third-party authorities. The proposed solution is lightweight, cost-effective, and suitable for institutional or departmental forensic environments. The implementation demonstrates that blockchain hashing can provide reliable protection for digital evidence while maintaining transparency and trustworthiness required for legal validation.