Securing Wireless Communication via Hardware-Based Packet Obfuscation

Obfuscation of the orthogonal frequency-division multiplexing (OFDM) physical layer is described in this paper as a means to enhance the security of wireless communication. The standardization of the communication channel between two trusted parties results in a variety of security threats, including vulnerabilities in WPA/WPA2 protocols that allow for the extraction of the software layer encryption key. Obfuscating the physical layer of the OFDM pipeline provides an additional layer of security in the event that the software layer key is compromised and allows for rolling updates of the physical layer key without altering the software layer key. The interleaver stage of the OFDM pipeline is redesigned to utilize a physical layer key, which is termed Phy-Leave. The Phy-Leave interleaver is evaluated through both MATLAB simulation and hardware prototyping on the Software Defined Communication (SDC) testbed using a Virtex6 FPGA. The implemented rolling physical layer key policy and Phy-Leave system resulted in a less than 1% increase in the area of a Virtex6 FPGA, demonstrating physical layer obfuscation as a means to increase the security of wireless communication without a significant cost in hardware.