Security and Entanglement in Quantum Key Distribution

Quantum key distribution (QKD) is a means of distributing a secure key between two parties, who wish to communicate privately. The security of the resulting shared key is independent of a potential eavesdropper's computational and technological power, if used as a one-time pad. The differential-phase-shift (DPS) QKD protocol has a number of practical advantages: its suitability for fibre transmissions; use of readily available telecommunication tools; no requirement for a single photon source (the generated states are assumed to be easily produced coherent states) and thus high communication efficiency. However, bounds for the unconditional security of DPS QKD have not yet been found. Here the security of the DPS QKD protocol is investigated, and a necessary condition for security is shown to be fulfilled.

Autorentext

Adriana Marais was born in 1983 in King William's Town, SouthAfrica. She studied Physics and Philosophy at the University ofCape Town, and obtained an MSc in Quantum Cryptography at theUniversity of KwaZulu-Natal in 2010, where she is currently doingresearch towards a PhD in the field of Quantum Biology.