Benjamin Gâteau

Risk-Based Methodology for Real-Time Security Monitoring of Interdependent Services in Critical Infrastructures

In today’s world, where most of the critical infrastructures (CI) are based on distributed systems, security failures have become very common, even within large corporations. The critical infrastructures are tightly interconnected, mutually dependent, and are exposed everyday to new risks.These (inter)dependencies generate potential cascading effects that may spread a malfunction or an attack from one part of the system to another dependent infrastructure.In this paper, we propose a risk-based methodology that aims to monitor interdependent services based on generic risks and assurance levels using the classical security properties: Confidentiality, Integrity and Availability. This allows each CI owner to monitor, react and adopt the best behavior corresponding to the security status of its different services.

Adopting trust and assurance as indicators for the reassignment of responsibilities in multi-agent systems

Multi-agent systems have been widely used in the literature, including for the monitoring of distributed systems. However, one of the unresolved issues in this technology remains in the reassignment of the responsibilities of monitoring agents when some of them become unable to meet their obligations. This paper proposes a new approach for solving this problem based on: (a) the gathering of evidence on whether the agent can or cannot fulfil the tasks it has been assigned and (b) the reassignment of the task to alternative agents using their trust level as a selection parameter. A weather station case study is proposed as an instantiation of the proposed model.

ARMAN: Agent-based Reputation for Mobile Ad hoc Networks

Reputation-based trust systems have received large attention as a mechanism to enforce cooperation in decentralized environment such as Mobile ad hoc Networks (MANET). Performance of the MANET results from the cooperation which may be selfish. In such context, avoiding entities that could exhibit malicious behaviour is a challenge. These malicious behaviours include on-off, selfishness, collusion and oscillating. In this paper, we proposed an agent-based reputation approach for MANET that has threefold goals: first it is an enhancement scheme for existing routing protocol in terms of quality of service such as packet delivery. Second, without any prior information, an evaluator agent can form a view about an evaluated agent by requesting and interpreting the reports provided by recommender even when the majority of these reports are unfair. This is done through the similarity of beliefs between agents. Finally the Dempster Shafer theory is used during the integration of information provided by recommender to reduce the uncertainty in trust evaluation.

Simulating Daily Mobility In Luxembourg Using Multi-Agent Based System.

This paper describes a daily mobility model which allows realizing urban simulation to help understanding future land use management policies. The main challenge in such urban simulation consists of how to evaluate future situations since where comparison with real data cannot be possible. The work presented in this paper is about solving this problem and encouraging results have been obtained. Experiments have been made within different scenarios in Luxembourg.