With the launch of the world's computer network protected by unbreakable quantum encryption, many people now find themselves trying to find out what it takes to develop this unbreakable encryption.
Quantum cryptography is completely different from the kinds of security schemes used on computer networks today. These are typically based on complex mathematical procedures which are extremely hard for outsiders to crack but not impossible given sufficient computing resources or time.
But quantum systems use the laws of quantum theory, which have been shown to be inherently unbreakable.
All quantum security schemes are based on the Heisenberg Uncertainty Principle, on the fact that you cannot measure quantum information without disturbing it, as he explained.
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.
This takes the security of networks a notch higher and even though this sounds a great deal, I have a feeling that when intrested people get to play with it, then somehow more on ways to find faults or break the encryption will emerge. The outline is that there are many ways a photon of light can encode a numerical key one of them being through the direction they are polarised.
bbc