Formal analysis of the FIDO 1.x protocol

Abstract

This paper presents a formal analysis of FIDO, a protocol developed by the FIDO Alliance project, and which aims to provide either a passwordless experience or an extra security layer for user authentication over the Internet. We model the protocol using the applied pi-calculus and run our analysis using ProVerif. Our analysis shows that ignoring some optional steps of the standard could lead to the implementation of a flawed authentication process. On the contrary, we prove that these steps are sufficient to ensure the expected security properties.