Abstract

Quantum Key Distribution (QKD) is a cryptographic primitive, which offers an extremely high security standard known as unconditional or information-theoretic security (see e.g. [1] and references therein), relying on intrinsically quantum properties of communication (light) signals. By definition QKD is a point-to-point key establishment protocol, which requires both a direct quantum channel for transmitting quantum signals and an additional error-free authentic classical channel for accompanying classical communication. Moreover, with current technology, QKD is limited in both rate and distance. Clearly all these features indicate that a single point-to-point connection – a QKD link – can find only restricted application and is relevant for certain specific high-security infrastructures.

© 2007 IEEE