A researcher has factored the RSA keys of a certificate authority dating back to the 1990s.
In a blog post published this week, the researcher describes tracking down and factoring the RSA private key used by a certificate authority that operated in the 1990s. The write-up quickly climbed the ranks on Hacker News, picking up 100 points and 20 comments within a day of publication. The headline claim is straightforward: keys that once anchored trust on the early web can still be broken today. That CA stopped operating long ago, but its old keys evidently weren't destroyed or forgotten thoroughly enough to stay unbreakable.
This fits a familiar pattern in crypto history. Many certificate authorities and TLS deployments from the 1990s used RSA keys short enough - often 512 or 768 bits - that they're now trivial to factor with commodity hardware, no clever attack required. It's the same lesson researchers drew from 2012's mass factoring of weak keys found online, and from the 2017 ROCA flaw in Infineon-generated keys: cryptographic debt from decades-old defaults doesn't expire just because the systems using it did.
The CA in question isn't signing anything anymore, so nobody's browser is at risk today. But it's a tidy reminder that 'dead' cryptographic material has a way of outliving the systems that retired it.