Physical-Layer Security for THz Communications via Orbital Angular Momentum Waves
Jongchan Woo, Muhammad Ibrahim Wasiq Khan, Mohamed I. Ibrahim, Ruonan Han, Anantha P. Chandrakasan, Rabia Tugce Yazicigil
Abstract
This paper presents a physically-secure wireless communication system utilizing orbital angular momentum (OAM) waves at 0.31THz. A trustworthy key distribution mechanism for symmetric key cryptography is proposed by exploiting random hopping among the orthogonal OAM-wave modes and phases. Keccak-f[400] based pseudorandom number generator provides randomness to phase distribution of OAM-wave modes for additional security. We assess the security vulnerabilities of using OAM modulation in a THz communication system under various physical-layer threat models as well as analyze the effectiveness of these threat models for varying attacker complexity levels under different conditions.