An enhanced cross-layer authentication mechanism for wireless communications based on PER and RSSI

Recently physical layer attributes and statistics have been exploited in securing wireless communications. However, one major obstacle of physical layer security techniques is that not all of these attributes are accessible in practical wireless communication platforms. More precisely, once the hardware of a physical transceiver is implemented, most of the physical layer attributes are not accessible due to the highly integrated circuits. Consequently, it becomes essential to develop implementable security enhancement techniques by utilizing all available attributes and statistics at different layers of wireless communication networks. In this paper, we consider the packet error rate (PER) and the received signal strength indicator (RSSI) in IEEE 802.11 networks to improve the wireless communication security. These two unique user and environment dependent attributes are readily available in most of the currently deployed IEEE 802.11 platforms. To enhance the spoofing attack detection capability, we propose a practical authentication scheme by monitoring and analyzing the PER and RSSI at the same time. The hypothesis testing model for the proposed authentication using PER and RSSI as two testing variables is presented. In addition, a decision rule for authentication, which is able to differentiate between a legitimate transmitter and a potential attacker by combining both attributes together, is developed. To evaluate the feasibility of our proposed scheme, lab experiments have been conducted using an IEEE 802.11g Atheros platform. The proposed authentication technique is validated by the experimental and simulation data. Our final authentication results confirm the improved spoofing detecting capability of the proposed technique over the single-variable based authentication.