Case Study: Hala Systems achieves immutable, court-admissible evidence to hold war criminals accountable with ConsenSys on Ethereum

Holding War Criminals Accountable with Immutable Evidence on the Ethereum Blockchain

Hala Systems, a social enterprise running the Sentry Early Warning System in Syria, needed a way to prove the integrity and chain-of-custody for reports and sensor data gathered in active conflict zones so that evidence could be trusted by courts and accountability organizations. ConsenSys (ConsenSys Social Impact) partnered with Hala to explore using the Ethereum blockchain and its SensuiMod API service to create an immutable reference for each incident without disrupting the Sentry user experience.

ConsenSys delivered a hybrid solution that hashes event data (SHA256), stores those hashes in a smart contract on the public Ethereum blockchain, and hosts encrypted report data off‑chain, with the SensuiMod AWS Lambda service creating, signing, and paying for transactions so reporters and IoT sensors never need ETH. The result is a publicly verifiable, tamper-evident record that strengthens legal admissibility and transparency; combined with Hala’s Sentry alerts (which have saved hundreds of lives and reduced airstrike lethality by an estimated 20–27% in studied areas), ConsenSys’s implementation provides measurable improvements in evidence integrity and accountability.

Hala Systems

Tobias Schneider

Research Fellow