Covert Communication Over Noisy Channels

Speaker:              Ligong Wang

Time:                   10:00, July. 9th.

Location:             SIST 2-215

Host:                    Prof. Youlong Wu

Abstract:

We consider the problem of communication over a noisy channel subject to the constraint that the probability that an eavesdropper who observes the channel outputs can detect the communication activity must be low. Specifically, the relative entropy (Kullback-Leiber divergence) between the output distributions when a codeword is transmitted and when no input is provided to the channel must be sufficiently small. For a discrete memoryless channel whose output distribution induced by the “off” input symbol is not a mixture of the output distributions induced by other input symbols, we show that the maximum amount of information that can be transmitted under this criterion grows like the square root of total communication time. The same is shown to hold for the discrete-time additive white Gaussian noise channel, and a broad class of non-Gaussian additive noise channels.

Bio:

Ligong Wang received the B.E. degree in electronic engineering from Tsinghua University, Beijing, China, in 2004, and the M.Sc. and Dr.Sc. degrees in electrical engineering from ETH Zurich, Switzerland, in 2006 and 2011, respectively. From 2011 to 2014, he was a Post-Doctoral Associate with the Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA. He joined CNRS, France, as a tenured Researcher (chargé de recherche) in 2014. Since 2023 he has been on leave of absence from the CNRS and working as a Senior Researcher with the Signal and Information Processing Laboratory at ETH Zurich.