Leveraging Polygon Blockchain and Zero-Knowledge Proofs for Secure Electronic Evidence Storage in Court: A Novel Framework

Abstract

The increasing digitization of modern society has led to a growing volume of digital information---such as emails, photos, videos, and electronic records---being presented as evidence in legal proceedings. However, traditional storage systems are costly, slow, and prone to server failures. To address these challenges, we propose a system leveraging blockchain and IPFS to store electronic evidence securely and reliably. Existing Layer 1 blockchain-based systems face three key limitations: (1) scalability issues with slow throughput and high costs under heavy traffic; (2) privacy risks due to public visibility of transaction data; and (3) impracticality of on-chain storage for large evidentiary files. Our system utilizes Polygon, a faster and more cost-effective Layer 2 blockchain, combined with IPFS for off-chain storage of documents, images, and videos. Each file is assigned a cryptographic hash stored on-chain to ensure integrity and tamper resistance. Smart contracts enforce role-based access control, restricting actions to authorized participants such as police officers, lawyers, and judges. Experimental evaluation with 10,000 transactions achieved approximately 14.29 TPS on modest hardware, with the potential for significantly higher throughput in optimized environments. This demonstrates the system's viability for both high-volume urban courts and resource-constrained rural settings. Overall, the proposed solution offers enhanced security, controlled access, reduced storage costs, and improved efficiency for digital evidence management in judicial systems.