Quantum Encryption as a Step Closer to Total Secrecy

The first computer network in the world protected by an “unbreakable” security system based on quantum encryption has been unveiled at a Viennese scientific conference.

The network handles the connection of six Siemens offices in Vienna and the neighboring Sankt Pölten town in Austria through 200 km of fiber cables provided by the respective company. Each of the locations was provided with a PC-sized boxful of electronic gear and a small amount of sensitive light detectors that would ensure the perfect progress of the whole encryption process.

Unlike modern security technology which relies on complicated mathematical algorithms which may be hard, but not impossible to crack, quantum cryptography is based on the 25-year old idea of IBM's Charles Bennett and Montreal University's Gilles Brassard which generated the unbreakable laws of quantum theory. Brassard, who attended the Vienna conference in order to see his idea put to work, explains, “All quantum security schemes are based on the Heisenberg Uncertainty Principle, on the fact that you cannot measure quantum information without disturbing it. Because of that, one can have a communications channel between two users on which it's impossible to eavesdrop without creating a disturbance. An eavesdropper would create a mark on it. That was the key idea”.

Practically, extremely feeble light beams of individual photons were raced at a rate of a million per second between the Austrian nodes. Upon detection, they would reveal an ultra-secret numerical key, holding user data, just like regular networks. The trick with these quantum encrypted light networks is that anyone who would try to interfere and obtain data would immediately be exposed, as the system would shut down the respective route, choosing an alternate one simultaneously. This re-routing ability proves the robustness of the technology, a much-appreciated feature by organizations relying on security such as banks. One of the nodes' operator, Dr. Hannes Huebel from Vienna University, reveals, “We are constantly in touch with insurance companies and banks, and they say it's nearly better that they lose 10m Euro than if the system is down for two hours, because that might be more damaging for the bank. So that's what we have to prove, that we have a reliable system that delivers quantum keys for several weeks without interruption, and then they might be more interested”.

In fact, the whole theory is built on Albert Einstein's (yes, again!) discovery of photons' concept and properties. The great physicist was against their odd behavior when related to the quantum theory, but he has recently been proved wrong by experiments like this one, which may soon lead to major discoveries in computing, cryptography and even teleportation.