Tuesday, January 1, 2008

update: quantum cryptography



about quantum cryptography
Quantum cryptography is the oldest and best developed application of the field of quantum information science. Although it is frequently perceived as an encryption method, it is really a scheme to securely distribute correlated random numbers between the communicating parties and thus better described as quantum key distribution (QKD). Any attempt at eavesdropping from a third party is guarantied to be detected by the laws of physics (quantum mechanics) and shows up as an increased error rate in the transmission (the QBER).

the xo laptop and quantum key distribution

Prof. Christian Kurtsiefer, Prof. Antia Lamas and others from the
Quantum Information Technology Lab
Quantum Optics Section
Department of Physics
National University of Singapore
2 Science Drive 3
117542 Singapore
have been at the 24C3, giving a lecture on Quantum Cryptography and Possible Attacks (Video) and demonstrating the hardware of a full working kit developed in the National University of Singapore for entanglement based QKD over a free space channel.

That device is accessible via usb and was built up at the ccc on the first floor. They got interested in the xo, sj gave them a few to play, and they started implementing their software for quantum key distribution.

After a few hours of tinkering with the kernel config, timezones (the xo's had to be synchronized with an accuracy of at least 0.5 sec) and software dependencies, they successfully tested the first 'entanglement based quantum key distribution' between xo laptops (Sa, 29.12.07)! And yes, they enjoyed it! : )