A few weeks ago I noted that the world had ended, and no one noticed. Well…
Their algorithm appears, at least for the moment, to encrypt information such that any attempt to decrypt it without the proper key will “change the behaviour of its elements”–in other words, trashing the information. Great news if it proves out, and given that it won a Turing award, I think it probably will.
Of course, truly unbreakable encryption is the nightmare scenario for governments and other control freaks the world over. I expect attempts to ban its use by individuals or groups other than governments will commence as soon as the first working program reaches wide-spread availability.
No, that’s not quite it. The Wikipedia entry for BB84 explains it well enough for a lay person, or at least some of us. It’s a method to detect whether a transmission of data has been observed or tampered with. This information could be, for example, a private key to be used for OTP encryption, or perhaps a seed to use for generating multiple keys for a series of OTP encryptions. I don’t know how this scales to the real world of world-wide communications. The Beeb is vastly over-simplifying it, and leaving a lot out. The bit stream going over the quantum channel isn’t encrypted at all, for example.
Looking at Wikipedia again, there are examples of Quantum key distribution networks in operation. Note, “key distribution”, i.e. a key for some other encryption operation. This functions similarly to how public-key cryptography is used to share secret keys, but uses quantum effects, rather than math. https://en.wikipedia.org/wiki/Quantum_key_distribution
However, don’t go back to “world ending” mode. There are people working on quantum-resistant encryption algorithms. IIRC, NIST has already approved one, though I don’t know if that’s for use, or for further evaluation.