Showing invariance compositionally for a process algebra for network protocols

TL;DR

This paper develops a mechanized, compositional framework in Isabelle/HOL for proving invariants in process algebras modeling network protocols, enabling scalable verification of network properties.

Contribution

It introduces a novel compositional technique for lifting node invariants to entire networks within a mechanized process algebra framework.

Findings

Mechanized process algebra in Isabelle/HOL for network protocols

A new technique for lifting local invariants to global network invariants

Enhanced proof automation for network protocol invariance

Abstract

This paper presents the mechanization of a process algebra for Mobile Ad hoc Networks and Wireless Mesh Networks, and the development of a compositional framework for proving invariant properties. Mechanizing the core process algebra in Isabelle/HOL is relatively standard, but its layered structure necessitates special treatment. The control states of reactive processes, such as nodes in a network, are modelled by terms of the process algebra. We propose a technique based on these terms to streamline proofs of inductive invariance. This is not sufficient, however, to state and prove invariants that relate states across multiple processes (entire networks). To this end, we propose a novel compositional technique for lifting global invariants stated at the level of individual nodes to networks of nodes.