Signal has just rolled out its quantum-safe cryptographic implementation. Ars Technica has a really good article with details: > Ultimately, the architects settled on a creative solution. Rather than bolt > KEM onto the existing double ratchet, they allowed it to remain more or less > the same as it had been. Then they used the new quantum-safe ratchet to > implement a parallel secure messaging system. > > Now, when the protocol encrypts a message, it sources encryption keys from > both the classic Double Ratchet and the new ratchet. It then mixes the two > keys together (using a cryptographic key derivation function) to get a new > encryption key that has all of the security of the classical Double Ratchet > but now has quantum security, too...

The headline is pretty scary: “China’s Quantum Computer Scientists Crack Military-Grade Encryption.” No, it’s not true. This debunking saved me the trouble of writing one. It all seems to have come from this news article, which wasn’t bad but was taken widely out of proportion. Cryptography is safe, and will be for a long time EDITED TO ADD (11/3): Really good explainer from Dan Goodin.