The Foul Adversary: Formal Models

Abstract

In classical notions of privacy in computer security, users attempt to keep their data private. A user that is bribed, extorted or blackmailed (i.e., coerced ) may not do so. To get a general model of coercion, we strengthen the Dolev-Yao adversary with the ability to coerce others, to the foul adversary. We show that, depending on the setting, subtly di↵erent abilities should be assigned to the adversary -whereas existing approaches are one-size-fits-all. The variations of the foul adversary are formalised and we provide a hierarchical relation in their strength. We further interpret the adversary models using several examples.

A blockchain-based decentralized booking system

“…In addition, the attacker behaviour in the current model is limited. Advanced attacker models can be defined for not only security but also privacy properties, following the style of (Dong and Muller, 2018), and the automatic verification algorithms need to be developed with respect to the attacks, for example using logic reasoning of attacks such as (Li et al ., 2017). In addition, the formal verification in this work only focuses on the application design; the implementation may introduce vulnerabilities; therefore, formal verification on the implementation is needed.…”