Claude traces NSA-supplied NIST curve seeds to a 1990s random number generator, settling a 25-year mystery

Anthropic says an internal Claude research model worked out in under 30 minutes where the NSA-supplied seeds behind NIST's ECDSA elliptic curves (P-192 through P-521) came from: output of lrand48, a standard 1990s C random-number generator, seeded with Unix timestamps from May 1997 to April 1998. The recovered generator states reproduce the published seeds exactly. Anthropic says this is not a cryptographic break or new weakness and makes the long-suspected NSA backdoor less plausible. It is donating the $36,864 bounty organized by cryptographer Filippo Valsorda to the Internet Security Research Group. Some parameters, including the B-163 seed and several base points, remain unexplained.