Blockchain and Artificial Intelligence for Forensic Evidence Chain-of-Custody Management: Towards Transparent and Tamper-Proof Judicial Systems Aligned with SDG 16 and SDG 9

This study outlines the creation, implementation, and assessment of a Blockchain–AI integrated chain-of-custody (CoC) framework for managing digital forensic evidence. The research sought to improve the integrity of evidence, transparency, and automation, tackling the shortcomings of conventional manual CoC processes. The suggested system was executed utilizing Hyperledger Fabric (6 nodes, PBFT consensus) and Ethereum testnet (10 nodes, PoA consensus), attaining an average block time of 1.2–3.8 seconds and transaction latency of 85–150 milliseconds. Smart contracts, RegisterEvidence(), VerifyCustody(), AccessGrant(), and LogActivity() streamlined the custody procedure, achieving a 99.6% integrity validation rate in blockchain-only mode and a complete 100% validation when paired with AI anomaly detection. The AI subsystem utilized a CNN–LSTM combined model that was trained on 500 labeled transaction logs, achieving 97.2% accuracy, 0.96 precision, 0.97 recall, and an F1-score of 0.965. Correlation analysis indicated a robust positive association (r = 0.94) between AI anomaly detection and blockchain integrity verification. Scalability evaluations over 100–5,000 transactions demonstrated throughput between 135 and 80 transactions per second (TPS), while memory usage rose from 32% to 77%, verifying effective resource utilization. The system exhibited strong alignment with SDG 16 (Peace, Justice, and Strong Institutions) and SDG 9 (Industry, Innovation, and Infrastructure), achieving scores of 0.98 for transparency, 0.95 for accountability, 0.96 for innovation, and 0.94 for digital infrastructure. Comparative benchmarks indicated significant enhancements compared to baseline CoC systems: +13.1% in integrity validation, + 60.7% decrease in latency, + 97.2% increase in accuracy, and + 50% improvement in scalability. These empirical findings confirm that the Blockchain–AI framework provides a secure, transparent, and smart forensic environment, capable of revolutionizing judicial evidence handling and enhancing institutional trust via automated, data-driven processes.