Diffie's Wireless Phone: Heterodyning-Based Physical-Layer Encryption

Jerry T. Chiang, Yih-Chun Hu
2013 MILCOM 2013 - 2013 IEEE Military Communications Conference  
We propose a physical-layer encryption scheme inspired by Diffie's telephone system. Instead of the usual XORthen-modulate encryption scheme, we propose using modulatethen-add, and show that the decryption operation can be implemented using the circuit operation of heterodyning. We then show that a slightly modified superheterodyne receiver performs decryption at no additional cost compared to existing receivers. Our proposed cryptosystem is significant to the research community for the
more » ... g reasons: 1) Our physical-layer encryption scheme uniquely outperforms other physical-layer security protocols by guaranteeing positive conditional secrecy capacity as long as Bob's signal-to-interference-and-noise ratio is above a threshold, even if Eve's channel condition is the same or significantly better than Bob's or if the channel between Alice and Bob is static; and 2) Our physical-layer encryption scheme shows that by removing a filter that the wireless circuit community has long considered to be necessary in the superheterodyne design, the modified receiver offers intriguing security features.
doi:10.1109/milcom.2013.87 dblp:conf/milcom/ChiangH13a fatcat:5ppxtog4hfbwxkflbm7vwmygoe