Abstract: Hiding transmitted signals is of paramount importance in many communication settings. While traditional security (e.g., encryption) prevents unauthorized access to message content, detection of the mere presence of a message by the adversary can have significant negative impact. This necessitates the use of covert communication, which not only protects the information contained in a transmission from unauthorized decoding, but also prevents the detection of a transmission in the first place. Although practical radio-frequency covert communication systems have been around since the advent of spread-spectrum, exploration of their fundamental limits is a new direction in information theory. Surprisingly, analysis of covert communication systems reveals that, while the Shannon capacity of a covert communication channel is zero, it still allows transmission of a large volume of covert data. This is true even when covert communications are secure from detection by a quantum-enabled adversary.
In this talk, I will present these fundamental results, focusing on their intuitive explanation, rather than their mathematical derivations. I will also describe a table-top proof-of-concept validation that paved the way for the ongoing experimental studies in quantum-secure covert communication.
Bio: Boulat A. Bash received the B.A. degree in economics from Dartmouth College in 2001and the M.S. and Ph.D. degrees in computer science from the University of Massachusetts, Amherst, MA, in 2008 and 2015, respectively. He is currently an Assistant Professor with the Electrical and Computer Engineering Department at the University of Arizona, Tucson, AZ. He was previously a Scientist with the Quantum Information Processing Group at Raytheon BBN Technologies, Cambridge, MA. His research interests include security, privacy, communications, signal processing, and information theory. He won an honorable mention at the 2015 NSA Best Scientific Cybersecurity Paper Competition, the RaytheonSpace and Airborne Systems Excellence in Engineering and Technology Award, and the NSF CAREER award.
Host: Gil Zussman
