“Scientists have sent messages encrypted using principles of quantum physics over a 250km German commercial telecommunications network, in a milestone towards next-generation data security.

Toshiba Europe researchers have used so-called quantum key distribution (QKD) cryptography to transfer messages over traditional communication systems in a way that would be safe from hackers.

QKD exploits a phenomenon known as quantum entanglement. This refers to the way two subatomic particles’ characteristics can be related, even when separated by a vast distance.

By measuring data from one particle, you can infer information from the other. This allows the pair to serve as keys that can exchange coded messages but are unreadable to outsiders.

The researchers were able to send such quantum messages with standard optical fibre and without specialist ultra-low temperature cooling equipment usually used for these kind of communications. They claim this is the first time such an extensive simplified quantum information exchange has been run on a commercial telecoms network.”

From Financial Times.