In under half an hour Claude finds where the NIST P-256 and other ECDSA curve seeds came from: lrand48 output seeded with a Unix timestamp
An internal research model solves a two-decade-old mystery in cryptography. Anthropic stresses this is not a weakness and, if anything, makes a backdoor less likely.
// Key points
- The seeds for the curves in NIST's 2000 FIPS 186-2 standard were supplied by the NSA without explanation; the popular story was that they were hashes of a humorous phrase.
- In October 2026 an employee asked an internal research model without pointing at that clue, and in under half an hour Claude found the origins of the P-192, P-224, P-256, P-384 and P-521 seeds.
- None were hash outputs: they came from the C library's lrand48 generator seeded with a Unix timestamp, 20 bytes per candidate, with P-256 at the 1,842nd candidate.
- Anthropic says this is not a cryptographic break, a new attack or a weakness in the curves, needs no action, and adds confidence that no backdoor was deliberately inserted.
Builder's takeNo code needs to change. What's worth noting is that a problem experts chased for years, down a misleading lead, fell in half an hour to a model without that bias. For a long-standing problem everyone on the team assumes they understand, I'd have a model rework it from the raw data rather than feed it our assumptions.
// Background · from #Anthropic
Full timeline →- Oct 19 Anthropic publishes its own employment data: by August, interactive AI agent hours outnumbered employees six to one, and junior technical hiring shrank as a share
- Oct 19 Anthropic sets up a Public Benefit Fund with 5% of its shares, subject to stockholder approval, plus 2% more for every 50% rise in value above a baseline
- Oct 19 Anthropic survey: 91% of its staff expect AI to make a Nobel-level discovery by 2030, against 39% of US adults