Resiliency and application to routing protocols in wireless sensor networks ; Résilience et application aux protocoles de routage dans les réseaux de capteurs

This thesis focuses on the security issues of multi-hop routing protocols for Wireless Sensor Networks (WSNs). The rapid deployment capabilities, due to the lack of infrastructure, as well as the self organized and potentially fault-tolerant nature of WSNs make them attractive for multiple applications spanning from environmental monitoring (temperature, pollution, etc.) to building industrial automation (electricity/gas/water metering, event detection, home automation etc). Security is particularly challenging in WSNs. Because of their open and unattended deployment, in possibly hostile environments, powerful adversaries can easily launch Denial-of-Service (Dos) attacks, cause physical damage to sensors, or even capture them to extract sensitive information (encryption keys, identities, addresses etc.). After node compromise, an adversary can seek to disrupt the functionality of network layer by launching attacks such as node replication, Sybil, Selective forwarding, Sinkhole, Wormhole etc. To cope with these "insider" attacks, stemming from node compromise, "beyond cryptography" algorithmic solutions must be envisaged to complement the traditional cryptographic solutions. Firstly, we propose the resiliency concept including our definition and a new metric to compare routing protocols. This method allows to aggregate meaningfully several parameters (quantitative information) and makes it easier to visually discern various tradeoffs (qualitative information), thus greatly simplifying the process of protocol comparison. Secondly, we propose the protocol behaviors enhancing resiliency. Our proposition consists in three strategies: (i) introduce random behaviors (ii) limit route length (iii) introduce data replication. These mechanisms are applied to several well known routing protocols to study their resiliency. Finally, a theoretical study of resiliency is introduced. We present an analytical study of biased random walks under attacks to confirm the results obtained through simulations. ; Les travaux réalisés ...