Anthropic Says Claude Traced NIST ECDSA Curve Seeds to a 1990S RNG

What happened

NIST adopted it in 2000 as part of the FIPS 186-2 Digital Signature Standard, which lists standard elliptic curves of varying sizes and security levels. Anthropic's Frontier Red Team reported in a research publication on October 16, 2026, that an internal Claude research model had traced the origins of the NIST ECDSA curve seeds to the C library's lrand48 random-number generator seeded with Unix timestamps, answering a provenance question that had been open since the NSA supplied the values without explanation. NIST is based in Gaithersburg, and its products and services include Federal Information Processing Standard. Anthropic is an artificial intelligence company based in San Francisco, and its products and services include Claude and Claude Code.

The Unexplained NSA Seeds ECDSA is the most widely used elliptic curve cryptography standard. For curves over prime and binary fields, the specification published a seed parameter whose hash value defines the coefficient b of the curve.

The NSA provided those seeds with no explanation or justification, and the post reproduces the P-256 seed, C49D3608 86E70493 6A6678E1 139D26B7 819F7E90, as an example of a value published with no information about where it came from. Neal Koblitz and Alfred Menezes summarized the controversy in the paper “A Riddle Wrapped in an Enigma,” and the question later drew an amateur investigation into the seeds’ origins and a bounty for whoever could find them. The leading account held that longtime NSA employee Jerry Solinas had generated the seeds as the hash of a humorous passphrase.