Supervisory Control and Data Acquisition (SCADA) systems are migrating from isolated to highly-interconnected large scale architectures. In addition, these systems are increasingly composed of standard Internet technologies and use public networks. Hence, while the SCADA functionality has increased, its vulnerability to cyber threats has also risen. These threats often lead to reduced system availability or compromised data integrity, eventually resulting in risks to public safety. Therefore, enhancing the reliability and security of system operation is an urgent need. Peer-to-Peer (P2P) techniques allow the design of self-organizing Internet-scale communication overlay networks. Two inherent resilience mechanisms of P2P networks are path redundancy and data replication. This paper shows how SCADA system's resilience can be improved by using P2P technologies. In particular, the two previously mentioned resilience mechanisms allow circumventing crashed nodes and detecting manipulated control data. © 2010 Springer-Verlag.