Information theory and cryptography based secured communication scheme for cooperative MIMO communication in wireless sensor networks

Emerging cooperative MIMO communication is a promising technology in improving communication performance for wireless sensor networks. However, the security problems inherent to cooperative communications also arise. In this paper, we propose a cross-layer secured communication scheme for cooperative MIMO communication in wireless sensor networks to overcome the external and active compromised nodes attacks. The scheme combines cryptographic technique implemented in higher layers with data assurance analysis at the physical layer to provide better communication security. An efficient key management system is proposed for the cryptographic processes. It provides secured communication and routing using a small number of keys shared between the clusters which cooperate on data transmission and reception. Although cryptography can ensure the confidentiality in the communications between authorized participants, it usually cannot prevent the attacks from compromised nodes. The situation where the cooperative nodes are compromised and try to corrupt the communications by sending garbled signals is also investigated in this paper. A novel information theory based detector that can identify the active compromised nodes and recover the symbols in transmission process at physical layer is proposed. When the compromised nodes are detected, the key management system calls the key revocation to isolate these nodes and reconfigure the cooperative MIMO network. Simulation results show that the proposed algorithm for compromised nodes detection is effective and efficient, and the accuracy of received information is significantly improved.