RSA is the encryption that underpins secure Internet messages. Without it, there would basically be no commercial Internet. So it was concerning to see a paper published saying that Chinese researchers have a quantum encryption technique that cracks RSA. Except, not so fast:
The paper from 24 researchers in China might have remained a matter for those well-versed in advanced mathematics, cryptography, and quantum computing – a fairly small set of people – but for the fact that it got noticed by cryptographer Bruce Schneier.
"This is something to take seriously," he wrote in his blog on January 3rd, 2023. "It might not be correct, but it’s not obviously wrong."
Schneier did not take a position on the paper, but the following day The Financial Times took notice in an article titled, "Chinese researchers claim to find way to break encryption using quantum computers."
Evidently they haven't.
Late that day, on January 4, Scott Aaronson, chair of computer science at The University of Texas at Austin, and director of its Quantum Information Center, offered a rebuttal with a succinct three word review of the paper: "No. Just No."
Crypto mathematics is notoriously hard to do right, and deceptively easy to screw up. It looks like this paper made an unwarranted assumption that a particular algorithm is much faster when using quantum cryptography. It's actually no faster than plain jane cryptography.
So secure Internet messages are safe, at least for now.