E-Witness: Preserve and Prove Forensic Soundness of Digital Evidence

In this demo we present E-Witness, a system that uses blockchain technology to prove the integrity and spatio-temporal properties of digital evidence captured through a smart-phone. The system consists of a smart-phone application that computes robust hash of pictures or videos taken from the phone camera, a location attestation service and a public blockchain which contains ledger entries to preserve the evidence file's hash and location certificate. The human witness can remain anonymous in this process. An investigator who receives the evidence (by any means) can verify the integrity and spatio-temporal claims of the evidence by querying the blockchain.