In security protocol analysis, the traditional choice to consider a single Dolev–Yao attacker is supported by the fact that models with multiple collaborating Dolev–Yao attackers are reducible to models with one Dolev–Yao attacker. In this paper, we take a fundamentally different approach and investigate the case of multiple non-collaborating attackers. We formalize a framework for multi-attack...

We address the proof-based development of cryptographic protocols satisfying security properties. Communication channels are supposed to be unsafe. Analysing cryptographic protocols requires precise modelling of the attacker’s knowledge. In this paper we use the event B modelling language to model the knowledge of the attacker for a class of cryptographic protocols called cascade protocols. The...

We study the enforcement of K-step opacity at runtime. In K-step opacity, the knowledge of the secret is of interest to the attacker within K steps after the secret occurs and becomes obsolete afterwards. We introduce the mechanism of runtime enforcer that is placed between the output of the system and the attacker and enforces opacity using delays. If an output event from the system violates K...

In the Target–Attacker–Defender differential game, an Attacker missile strives to capture a Target aircraft. The tries escape and is aided by Defender which aims at intercepting Attacker, before latter manages close in on Target. conflict between these intelligent adversaries naturally modeled as zero-sum game. Game of Degree when able win game has not been fully solved, it addressed this paper...