1. Problem Statement

Traditional evidence storage systems rely on centralized servers, making them vulnerable to unauthorized modification, undetectable tampering, administrative manipulation, and lack of cryptographic proof. The challenge was designing a system that guarantees integrity even if storage nodes are compromised.

2. Research Focus

• Deterministic Hash Verification: Implemented SHA-based hashing for file identity, ensuring consistent hash reproduction for validation.
• On-Chain Integrity Anchoring: Designed smart contract data structures to store file hash references, enabling immutable timestamp verification via Ethereum.
• Off-Chain Distributed Storage: Integrated IPFS for decentralized hosting, maintaining separation between storage and verification layers.
• Tamper Detection Model: Compared recomputed hashes against anchored blockchain records, eliminating reliance on centralized trust.

3. Architectural Insight

The core architectural insight was the strict decoupling of the Integrity Layer (Ethereum) and Storage Layer (IPFS). This separation reduces cost, improves scalability, and maintains immutability without bloating on-chain data.

4. Technical Contributions & Security Considerations

Key contributions include smart contract-based hash anchoring, a deterministic integrity comparison pipeline, role-based backend services, and a metadata indexing layer configured seamlessly for an Oracle Cloud production deployment. Immutable on-chain records prevent retroactive alteration, coupled with infrastructure hardening at the server level (Nginx, rate limiting).

5. Outcome

Demonstrated a functional decentralized evidence system capable of cryptographically verifiable integrity, distributed file hosting, and production-ready backend integration. The research validated that hybrid integrity anchoring provides strong tamper resistance while maintaining operational efficiency.