Cross-Layer Attack and Defense in Cognitive Radio Networks

The existing research on security issues in cognitive radio networks mainly focuses on attack and defense in individual network layers. However, the attackers do not necessarily restrict themselves within the boundaries of network layers. In this paper, the authors design cross-layer attack strategies that can largely increase the attackers' power or reducing their risk of being detected. As a case study, they investigate the coordinated report-false-sensing-data attack (PHY layer) and small-back-off-window attack (MAC layer). Furthermore, they propose a trust-based cross-layer defense framework that relies on abnormal detection in individual layers and cross-layer trust fusion. Simulation results demonstrate that the proposed defense framework can significantly reduce the maximum damage caused by attackers.