Introduction
Criminal law cases heavily rely on various types of evidence, including physical, scientific, and witness testimonies, to ensure credibility and reliability in court. Recently, digital evidence, which includes data from electronic devices, has become crucial in all types of crimes, not just electronic ones. Maintaining the integrity of both physical and digital evidence is essential, requiring meticulous documentation through a chain of custody. Digital evidence poses unique challenges due to its susceptibility to alteration. To address this, a proposed system leverages blockchain technology to ensure the integrity of criminal evidence. Blockchain’s tamper-resistant nature and transparency make it ideal for evidence management.
Description
The proposed integrity system ensures the secure and transparent validation of digital evidence using blockchain and smart contracts, specifically leveraging Hyperledger Fabric technology. To interact with the smart contracts, two APIs have been created to isolate the blockchain related operation to the use case specific one. In addition, smart contracts emit events for each transaction, allowing users to subscribe to notifications when records are stored and access them through a graphical blockchain monitor. Due to the large size of digital evidence files, they are stored locally, while their hashes are recorded on the blockchain to ensure integrity without revealing sensitive data. SHA2-256 is suggested for hashing, allowing for secure and efficient verification. This architecture enhances performance and security, ensuring evidence remains trustworthy and admissible in court.
Validation
The use of blockchain for verifying the integrity of criminal evidence has proven effective in car accident analysis, where maintaining the chain of custody is crucial, especially with advanced techniques like 3D reconstruction and energy analysis. A standalone tool has been developed to perform these analyses using images from cameras as evidence and integrating the blockchain-based system to secure them. This functionality, named “Protect Project,” generates and stores the unique hash codes for each file, ensuring they are securely registered. Another module, “Check Project,” verifies the integrity of these files by comparing their hashes. This integration enhances the security, fairness, and trustworthiness of the 3D reconstruction tool, ensuring the evidence remains unaltered.
Conclusions
The blockchain based integrity system enhances the security, usability, and adaptability of criminal evidence chain of traditional custody solutions requiring evidence integrity. Utilizing Hyperledger Fabric, the system leverages blockchain’s inherent features like integrity, traceability, and availability. Usability improvements include independent REST APIs for easy interaction and a blockchain monitor to isolate users from blockchain complexities. The result is a more reliable, secure, and user-friendly evidence integrity validation prototype that has been validated in a 3D reconstruction tool used in car accidents analyses.
References
Regueiro, C., Urquizu, B., Barguilla, X., Ruiz de Oña, E., Ospina, A., Gonzalez-Aguilera, D. (2024). Leveraging Hyperledger Fabric for Criminal Evidence Integrity-Proofs. 6th International Congress on Blockchain and Applications, 2024, Salamanca (Spain).