Induced-Photorefraction Attack against Quantum Key Distribution

Abstract

Lithium niobate (LN) devices have been widely adopted in systems for quantum key distribution (QKD), but the photorefractive effect in LN devices can be exploited as a potential loophole for malicious attacks by eavesdroppers. This work points out a vulnerability of LN devices of which manufacturers and users must become aware, so that appropriate countermeasures may be implemented. Moreover, the physical mechanism and techniques introduced in this work open an important avenue to the security analysis of QKD systems.