Biblio
Cyber-physical systems are an important component of most industrial infrastructures that allow the integration of control systems with state of the art information technologies. These systems aggregate distinct communication platforms and networked devices with different capabilities. This integration, has brought into play new uncertainties, not only from the tangible physical world, but also from a cyber space perspective. In light of this situation, awareness and resilience are invaluable properties of these kind of systems. The present work proposes an architecture based on a distributed middleware that relying on a hierarchical multi-agent framework for resilience enhancement. The proposed architecture takes into account physical and cyber vulnerabilities and guarantee state and context awareness, and a minimum level of acceptable operation, in response to physical disturbances and malicious attacks. This framework was evaluated on an IPv6 test-bed comprising several distributed devices, where performance and communication links health are analysed. Results from tests prove the relevance and benefits of the proposed approach.
Smart grid is a cyber-physical system that integrates power infrastructures with information technologies. To facilitate efficient information exchange, wireless networks have been proposed to be widely used in the smart grid. However, the jamming attack that constantly broadcasts radio interference is a primary security threat to prevent the deployment of wireless networks in the smart grid. Hence, spread spectrum systems, which provide jamming resilience via multiple frequency and code channels, must be adapted to the smart grid for secure wireless communications, while at the same time providing latency guarantee for control messages. An open question is how to minimize message delay for timely smart grid communication under any potential jamming attack. To address this issue, we provide a paradigm shift from the case-by-case methodology, which is widely used in existing works to investigate well-adopted attack models, to the worst-case methodology, which offers delay performance guarantee for smart grid applications under any attack. We first define a generic jamming process that characterizes a wide range of existing attack models. Then, we show that in all strategies under the generic process, the worst-case message delay is a U-shaped function of network traffic load. This indicates that, interestingly, increasing a fair amount of traffic can in fact improve the worst-case delay performance. As a result, we demonstrate a lightweight yet promising system, transmitting adaptive camouflage traffic (TACT), to combat jamming attacks. TACT minimizes the message delay by generating extra traffic called camouflage to balance the network load at the optimum. Experiments show that TACT can decrease the probability that a message is not delivered on time in order of magnitude.