QuADTool: Attack-Defense-Tree Synthesis, Analysis and Bridge to Verification

TL;DR

QuADTool is a comprehensive framework for synthesizing, analyzing, and verifying attack-defense trees with probabilistic and cost considerations, accommodating imprecise statistical data for more realistic security risk assessments.

Contribution

It introduces methods to handle PAC (probably approximately correct) data in attack-defense tree analysis, providing rigorous bounds on uncertainty and integrating with existing verification tools.

Findings

Supports analysis with imprecise probabilistic data

Provides bounds on uncertainty in risk estimates

Integrates with model checkers for verification

Abstract

Ranking risks and countermeasures is one of the foremost goals of quantitative security analysis. One of the popular frameworks, used also in industrial practice, for this task are attack-defense trees. Standard quantitative analyses available for attack-defense trees can distinguish likely from unlikely vulnerabilities. We provide a tool that allows for easy synthesis and analysis of those models, also featuring probabilities, costs and time. Furthermore, it provides a variety of interfaces to existing model checkers and analysis tools. Unfortunately, currently available tools rely on precise quantitative inputs (probabilities, timing, or costs of attacks), which are rarely available. Instead, only statistical, imprecise information is typically available, leaving us with probably approximately correct (PAC) estimates of the real quantities. As a part of our tool, we extend the standard analysis techniques so they can handle the PAC input and yield rigorous bounds on the imprecision and uncertainty of the final result of the analysis.