A Simple Auditable Fingerprint Authentication Scheme Using Smart-Contracts

Biometric authentication, and notably using fingerprints, are now common. Despite its usability, biometrics have however a caveat which is the impossibility of revocation: once the raw fingerprint is breached, and depending on the technology of the reader, it is impossible to stop an illegitimate authentication. This places a focus on auditing both to detect fraud and to have clear indications that the fingerprint has been breached. In this paper we show how to take advantage of the immutability property of Blockchains to design an auditable protocol based on Diffie-Hellman key exchange with applications to fingerprint authentication.