On the Protocol Composition Logic PCL

TL;DR

This paper critically examines the Protocol Composition Logic (PCL), identifies its limitations and issues, and proposes solutions to improve its soundness and applicability in formal security protocol analysis.

Contribution

It provides a detailed critique of PCL, highlights its restrictions, and offers potential solutions to address identified problems.

Findings

Identified fundamental problems with PCL and its extensions.

Showed that some PCL proofs are invalid or rely on unsound axioms.

Proposed solutions to enhance the soundness of PCL.

Abstract

A recent development in formal security protocol analysis is the Protocol Composition Logic (PCL). We identify a number of problems with this logic as well as with extensions of the logic, as defined in [DDMP05,HSD+05,He05,Dat05,Der06,DDMR07]. The identified problems imply strong restrictions on the scope of PCL, and imply that some currently claimed PCL proofs cannot be proven within the logic, or make use of unsound axioms. Where possible, we propose solutions for these problems.