Automated Verification of Accountability in Security Protocols

TL;DR

This paper introduces a protocol-agnostic, automated method for verifying accountability in security protocols, capable of identifying misbehaving parties and detecting violations through trace property analysis.

Contribution

It presents a mechanized, highly automated approach to verify accountability in security protocols, applicable across various examples and demonstrating soundness and completeness.

Findings

Effective verification of accountability in multiple protocols

Automated detection of misbehavior and security violations

Applicability to real-world protocols like Certificate Transparency

Abstract

Accountability is a recent paradigm in security protocol design which aims to eliminate traditional trust assumptions on parties and hold them accountable for their misbehavior. It is meant to establish trust in the first place and to recognize and react if this trust is violated. In this work, we discuss a protocol agnostic definition of accountability: a protocol provides accountability (w.r.t. some security property) if it can identify all misbehaving parties, where misbehavior is defined as a deviation from the protocol that causes a security violation. We provide a mechanized method for the verification of accountability and demonstrate its use for verification and attack finding on various examples from the accountability and causality literature, including Certificate Transparency and Kroll Accountable Algorithms protocol. We reach a high degree of automation by expressing accountability in terms of a set of trace properties and show their soundness and completeness.