Secure cryptography with real-world devices is now a realistic possibility

A key role for quantum entanglement - one of the two ion traps used Credit: David Nadlinger/University of Oxford New research published in Nature explains how an international team of researchers have, for the first time, experimentally implemented a type of quantum cryptography considered to be the 'ultimate', 'bug-proof' means of communication. In an experiment built upon three decades of fundamental research, experimental work at the Department of Physics , University of Oxford - with theoretical contributions from ETH Zurich, EPFL, the University of Geneva in Switzerland, and the French Alternative Energies and Atomic Energy Commission (CEA) - demonstrated a complete quantum key distribution protocol immune to the vulnerabilities and defects of physical devices that plague current quantum protocols. The experiment proves a much stronger form of security than is currently attainable using classical computers. Existing implementations of 'quantum key distribution' (QKD) rely on communicating between 'trusted' quantum devices (and so offers the potential for quantum hacking). The newly demonstrated approach allows secure communication between devices without needing to know much about them. This important breakthrough paves the way for secure cryptography for real-world devices, and for further quantum information applications based on a principle of device independence. Professor David Lucas, Department of Physics, University of Oxford explained: 'The real breakthrough here is that we were not just able to show that our quantum network had theoretically good enough performance to do this new kind of QKD, but that we were actually able to do it in practice and get all the way to distributing a shared secret key.