Key to combat hacking - Quantum Cryptography

Quantum cryptography could well be the first application of quantum mechanics at the individual quanta level. Quantum cryptography is an approach to securing communications based on certain phenomena of quantum physics. Unlike traditional cryptography, which employs various mathematical techniques to restrict eavesdroppers from learning the contents of encrypted messages, quantum cryptography is focused on the physics of information. The process of sending and storing information is always carried out by physical means, for example photons in optical fibres or electrons in electric current.

Eavesdropping can be viewed as measurements on a physical object---in this case the carrier of the information. What the eavesdropper can measure, and how, depends exclusively on the laws of physics. Using quantum phenomena such as quantum superpositions or quantum entanglement one can design and implement a communication system which can always detect eavesdropping. This is because measurements on the quantum carrier of information disturb it and so leave traces.

Some commercially-available products have appeared based on quantum cryptography, for example, ID Quantique or MagiQ.