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.
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Physical Layer Encryption for Wireless OFDM Communication Systems
Our everyday lives are impacted by the widespread adoption of wireless communication systems integral to residential, industrial, and commercial settings. Devices must be secure and reliable to support the emergence of large scale heterogeneous networks. Higher layer encryption techniques such as Wi-Fi Protected Access (WPA/WPA2) are vulnerable to threats, including even the latest WPA3 release. Physical layer security leverages existing components of the physical or PHY layer to provide a low-complexity solution appropriate for wireless devices. This work presents a PHY layer encryption technique based on frequency induction for Orthogonal Frequency Division Multiplexing (OFDM) signals to increase security against eavesdroppers. The secure transceiver consists of a key to frequency shift mapper, encryption module, and modified synchronizer for decryption. The system has been implemented on a Virtex-7 FPGA. The additional hardware overhead incurred on the Virtex-7 for both the transmitter and the receiver is low. Both simulation and hardware evaluation results demonstrate that the proposed system is capable of providing secure communication from an eavesdropper with no decrease in performance as compared with the baseline case of a standard OFDM transceiver. The techniques developed in this paper provide greater security to OFDM-based wireless communication systems.
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- NSF-PAR ID:
- 10178107
- Date Published:
- Journal Name:
- Journal of Hardware and Systems Security
- ISSN:
- 2509-3428
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s41635-020-00097-8
