Covert Communication: From Classical to Quantum
Boulat A. Bash, University of Arizona
1-2pm 8th Jul 2025
Abstract
In this talk, Professor Boulat A. Bash will explore why 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 a 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. Furthermore, unlike typical (non-covert) communication, covert communication systems substantially benefit from channel dynamics. Classical covert communication also presents a unique operating regime for deriving significant gain from pre-shared quantum entanglement. However, the necessity for noise to hide transmissions challenges covert communication of quantum data (i.e., qubits). In this talk, I will present these fundamental results, focusing on their intuitive explanation, rather than their mathematical derivations. I will conclude with directions for future research.
Short Bio