Quantum secured bank transfer

An entangled state quantum cryptography system that operated in a real world application scenario was presented for the first time in April 2004. The full key generation protocol was performed in real time between two distributed embedded hardware devices, which were connected by 1.45 km of optical fiber that has been explicitly installed for this experiment in the Vienna sewage system.

The generated quantum key was immediately handed over and used by an secure communication application.

In the experiment it was possible to distribute secure quantum keys on demand between the headquarters of an Austrian bank and the Vienna city hall using polarization entangled photon pairs in an adopted BB84 protocol. The produced key was directly handed over to an application that was used to send an quantum secured online wire transfer from the City Hall to the bank.

The experiment demonstrated the operation of an entangled state quantum cryptography prototype system.
The results clearly show that entangled state systems provide a good alternative for weak coherent pulse systems, with the additional benefit of making a beamsplitter attack impossible and thus being closer to the ideal BB84 quantum cryptography idea than weak coherent pulse based systems.

A. Poppe, A. Fedrizzi, R. Ursin, H. R. Böhm, T. Lörunser, O. Maurhardt, M. Peev, M. Suda, C. Kurtsiefer, H. Weinfurter, T. Jennewein, and A. Zeilinger

Practical quantum key distribution with polarization entangled photons
Opt. Express 12, 3865-3871 (2004)
www.arxiv.org/abs/quant-ph/0404115