Physical layer encryption using fixed and reconfigurable antennas

Traditionally, antenna systems have been designed to achieve reliable wireless communication, while the problem of securing that communication from eavesdropping was left to mathematical cryptography. Recent research into physical layer encryption shows that jointly designing for reliability and secrecy at the physical layer may be a better solution. Physical layer encryption involves techniques that ensure a signal is information-theoretically secure, meaning that an eavesdropper with infinite time and computational resources will not be able to decode a message. Such techniques include purposely broadcasting artificial noise, transmitting direction-dependent signals, and opportunistic communications. This work addresses different methods for broadcasting artificial noise using fixed arrays, including tradeoffs with power usage and computational complexity. In addition, a method of producing direction-dependent distortion using reconfigurable arrays is also shown. These two methods are combined and shown to be more secure and power-efficient than either in isolation. An analysis of secrecy rates through mutual information makes it possible to compare the performance of all the various secure communication techniques. Simulations with various wireless channels as well as an experimental test using a fixed and reconfigurable array are presented.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2013

Author dc:creator

• Daly, Michael

Contributors dc:contributor

• Bernhard, Jennifer T.
• Cangellaris, Andreas C.
• Jones, Douglas L.
• Franke, Steven J.

• physical layer encryption
• artificial noise
• reconfigurable antennas
• secrecy capacity

Statement dc:rights

• Copyright 2012 Michael P. Daly

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/42321

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/42321