OSC Colloquium: Matthieu Bloch, "Towards Covert and Secret Quantum Networks"

Abstract(s): 

Despite steady progress in “post-quantum” cryptography, quantum-secured communication, especially in the form of Quantum Key Distribution (QKD), remains to date the only unconditionally secure technology to distribute secret keys. Quantum communication has effectively “leaped out of the lab” as most recently demonstrated in January 2018 with the deployment of a satellite-relayed intercontinental quantum network between China and Austria, leveraging the unique possibilities offered by the Micius quantum communication satellite.

We will discuss the possibility of deploying quantum key distribution that are also covert, in the sense of being provably undetectable by an adversary. While covert key generation over quantum channels is not possible under the same assumptions than QKD, we will show that, perhaps surprisingly, covert secret key generation is possible under mild assumptions regarding the quantum channels. In particular, we will provide a more nuanced perspective regarding the impossibility of covert key expansion in covert quantum key distribution. Time permitting, we will also discuss the construction of reconciliation algorithms for covert secret key generation, where the main challenge is to efficiently process the diffuse information that is embedded in covert signals. We show that astute signaling and coding techniques enable one to "concentrate" the information and approach the information-theoretic performance with low-complexity. 

Speaker Bio(s): 

Matthieu R. Bloch is a Professor in the School of Electrical and Computer Engineering at Georgia Tech. He received the Engineering degree from Supélec, Gif-sur-Yvette, France, the M.S. degree in Electrical Engineering from the Georgia Institute of Technology, Atlanta, in 2003, the Ph.D. degree in Engineering Science from the Université de Franche-Comté, Besançon, France, in 2006, and the Ph.D. degree in Electrical Engineering from the Georgia Institute of Technology in 2008. In 2008-2009, he was a postdoctoral research associate at the University of Notre Dame, South Bend, IN. Since July 2009, Dr. Bloch has been on the faculty of the School of Electrical and Computer Engineering, and from 2009 to 2013 Dr. Bloch was based at Georgia Tech Lorraine. His research interests are in the areas of information theory, error-control coding, wireless communications, and cryptography. Dr. Bloch has served on the organizing committee of several international conferences; he was the chair of the Online Committee of the IEEE Information Theory Society from 2011 to 2014, an Associate Editor for the IEEE Transactions on Information Theory from 2016 to 2019, and he has been on the Board of Governors of the IEEE Information Theory Society since 2016 and currently serves as the 2nd Vice-President. He has been an Associate Editor for the IEEE Transactions on Information Forensics and Security since 2019. He is the co-recipient of the IEEE Communications Society and IEEE Information Theory Society 2011 Joint Paper Award and the co-author of the textbook Physical-Layer Security: From Information Theory to Security Engineering published by Cambridge University Press.