This is maybe the most science-fictional headline I’ve ever seen: Government Lab Reveals It Has Operated Quantum Internet for Over Two Years. The article says things like:
once at the hub, they are converted to conventional classical bits and then reconverted into quantum bits to be sent on the second leg of their journey.
If someone told me about this, I’d have taken it about as seriously as “AI just around the corner” or “quantum computer renders all encryption obsolete.” “Cold fusion is finally here!” I’d have taken more seriously.
The article’s short on details, but I think I get the gist of it: your computer’s quantum network card randomly generates a one-time pad with quantum-entangled pairs of particles whose wave function collapses when half of them hit the quantum router. The one-time pad can’t be eavesdropped upon, because there isn’t anything to eavesdrop on because quantum physics is freakin’ magic. Then for the lifetime of the connection, both sides use this one-time pad to encrypt their traffic, which is sent conventionally.
Since the message is decrypted at the router, it’s only that first leg of the trip that’s über-secure; things are normal for the rest of your traffic’s trip.
After two years, they were using their quantum internet mostly to exchange pictures of Schrödinger’s cat.