Abstract

Computational encryption, information-theoretic secrecy and quantum cryptography offer progressively stronger security against unauthorized decoding of messages contained in communication transmissions. However, these approaches do not ensure stealth—that the mere presence of message-bearing transmissions be undetectable. We characterize the ultimate limit of how much data can be reliably and covertly communicated over the lossy thermal-noise bosonic channel (which models various practical communication channels). We show that whenever there is some channel noise that cannot in principle be controlled by an otherwise arbitrarily powerful adversary—for example, thermal noise from blackbody radiation—the number of reliably transmissible covert bits is at most proportional to the square root of the number of orthogonal modes (the time-bandwidth product) available in the transmission interval …

Date

October 19, 2015

Authors

Boulat A Bash, Andrei H Gheorghe, Monika Patel, Jonathan L Habif, Dennis Goeckel, Don Towsley, Saikat Guha

Journal

Nature communications

Volume

6

Issue

1

Pages

8626

Publisher

Nature Publishing Group UK