Secure cooperative MIMO communications under active compromised nodes

Emerging cooperative MIMO communication is a promising technology in improving communication quality for wireless sensor networks. However, the security problems inherent to cooperative communications also arise. In this paper we investigate the situation where some of the cooperative nodes are compromised and try to corrupt the communications by sending garbled signals. To combat the compromised nodes, we extended our previous work and proposed compromised nodes detection algorithms for three more general scenarios. These scenarios include having different numbers of nodes in the transmitting and receiving clusters, having multiple compromised nodes in the transmitting cluster, and having multiple compromised nodes in both the transmitting and receiving clusters. These algorithms are then integrated into a cross-layer security scheme for secure cooperative MIMO network. This scheme combines cryptographic technique implemented in higher layers with proposed data assurance analysis at the physical layer to provide better security. Simulations show that the proposed algorithms for compromised nodes detection are effective and efficient. Simulations also show that the accuracy of received information is significantly improved.