Diffie's wireless phone: Heterodyning-based physical-layer encryption

Jerry T. Chiang, Yih Chun Hu

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We propose a physical-layer encryption scheme inspired by Diffie's telephone system. Instead of the usual XOR-then-modulate encryption scheme, we propose using modulate-then-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 following 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.

Original languageEnglish (US)
Title of host publicationProceedings - 2013 IEEE Military Communications Conference, MILCOM 2013
Number of pages6
StatePublished - Dec 1 2013
Event2013 IEEE Military Communications Conference, MILCOM 2013 - San Diego, CA, United States
Duration: Nov 18 2013Nov 20 2013

Publication series

NameProceedings - IEEE Military Communications Conference MILCOM


Other2013 IEEE Military Communications Conference, MILCOM 2013
Country/TerritoryUnited States
CitySan Diego, CA

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


Dive into the research topics of 'Diffie's wireless phone: Heterodyning-based physical-layer encryption'. Together they form a unique fingerprint.

Cite this