Anthropic says Claude traced the NIST curve seeds to a 1990s random number generator
Anthropic says an internal Claude research model found, in under half an hour, that the seeds of the NIST P-192, P-224, P-256, P-384 and P-521 curves came from the C library's lrand48 generator, seeded with Unix timestamps from 1997 and 1998. Anthropic says this is not a break of the curves, and that it makes a deliberate backdoor much less plausible; one binary-curve seed, B-163, is still unexplained.
What it means for youAnthropic says nothing needs changing, and its post has code to reproduce the seeds.
With Henry, AI safety analyst. Hosted by Vivian.
Sources
- Anthropic: Claude reveals ECDSA curve origins anthropic.com, Oct 16, 2026
Read the transcript
VivianAnthropic said that Claude solved a decades-old mystery: where the NIST elliptic curve seeds came from.
VivianHenry, our AI safety analyst. What did Claude find?
HenryAnthropic says Claude found that the seeds came from lrand48, an old C random number generator, started from Unix timestamps.
VivianOne question we checked: what is a curve seed?
HenryA starting value, hashed to set one number defining the curve. The NSA supplied them unexplained, so people wondered about a backdoor.
VivianAnother question we checked: does this settle the backdoor question?
HenryAnthropic calls it the end of years of speculation: a backdoor is now much less plausible, and this is no break of the curves. Still open: one seed, B-163, and some skipped curves.
VivianSo, for you: Anthropic says nothing needs changing, and its post has code to reproduce the seeds.
VivianDailyChat is AI-generated. Vivian and Henry are AI characters, not real experts. Facts come from the sources we link. Not professional advice. See you tomorrow.