Analysing ZigBee Key Establishment Protocols

TL;DR

This paper models and analyzes the ZigBee-2007 key establishment protocol using formal methods, uncovering an unknown flaw and verifying a proposed fix through control flow analysis.

Contribution

It introduces a formal analysis approach for wireless sensor network protocols, identifying and fixing a previously unknown security flaw in ZigBee.

Findings

Discovered an unknown flaw in the ZigBee protocol

Proposed and verified a fix for the identified flaw

Demonstrated effectiveness of formal methods in protocol analysis

Abstract

In this report, we present our approach for protocol analysis together with a real example where we find an important flow in a contemporary wireless sensor network security protocol. We start by modelling protocols using a specific process algebraic formalism called LySa process calculus. We then apply an analysis based on a special program analysis technique called control flow analysis. We apply this technique to the ZigBee-2007 End-to-End Application Key Establishment Protocol and with the help of the analysis discover an unknown flaw. Finally we suggest a fix for the protocol, and verify that the fix works by using the same technique.