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.

Cryptocurrencies such as Bitcoin have been one of the new major technologies of the last decade. In this paper, we assess the security of Bitcoin using attack-defense trees, an established formalism to evaluate the security of systems. In this paper, our main contributions are as follows: (1) We provide an extended attack-defense tree model for attacks on Bitcoin. (2) We demonstrate the general usability of existing analysis methods for attack-defense trees in this context. (3) We highlight further research directions necessary to extend attack-defense trees to a full-fledged overarching model for security assessment.