#cryptography

A researcher proved that the private keys of eight eMudhra intermediate certificate authorities, chaining to roots trusted by Mozilla, Microsoft, Apple and Chrome, were compromised, and reported it on October 17. The disclosure site says the keys were incorrectly generated and anyone could recover them from the certificates since April 2025. Security researcher Scott Helme says each key was a single byte (one was literally 4) and he recovered all eight in under a second. Browsers blocked the intermediates within days, and because no certificates from them appeared in Certificate Transparency logs, CT-enforcing browsers were protected, but curl, Python, Go, CI pipelines and embedded devices that don't check revocation or CT need updated CA bundles.

On October 22 eMudhra said it will exit the global SSL/TLS business, about 1% of its revenue, saying it revoked the CAs within 14 hours, no end-entity certificates were issued from them, and scrutiny was out of proportion.

Three Hacker News threads questioned how a CA passed audits with such keys, debated whether the web's CA system needs replacing, and criticized eMudhra's statement.

Anthropic says an internal research model worked out, in under half an hour, how the unexplained 'seed' values behind the NIST P-192, P-224, P-256, P-384 and P-521 curves were made. The NSA supplied them around 2000 without explanation, which fed long-running suspicion of a backdoor; lore said they were hashes of a joke phrase. Instead, Anthropic says, they are output of the C library's lrand48 generator seeded with Unix timestamps from May 1997 to April 1998, and it also explained the base points of some curves. Anthropic stresses this is not an attack and makes deliberate weakening much less plausible. Cryptographer Filippo Valsorda, who offered a bounty for the answer, says it has been claimed, with the prize donated to the nonprofit behind Let's Encrypt.

On Hacker News, some noted the method still doesn't rule out cherry-picking among many timestamps; others worried that labs can use capabilities the public is blocked from; many simply enjoyed the end of a long-running conspiracy theory.