Claude reveals the origin of the ECDSA curve parameters
Claude reveals ECDSA curve origins
Anthropic says its internal research model Claude found in less than half an hour the origin of the seeds for the NIST P-192, P-224, P-256, P-384, and P-521 curves: they are not the output of a hash algorithm, but were produced by the C library lrand48 random number generator seeded with Unix timestamps. Anthropic employees posed this question in October 2026, and Claude identified the output characteristics of the 1990s PRNG, then used the LLL algorithm to recover the truncated linear congruential generator state, obtaining the timestamp corresponding to each seed; for example, P-256 required 1842 iterations. Claude also found that the six curve base points generated in 1997 came from FreeLIP's random number generator, with seeds from 20000 to 20517. The seed bounty of $36,864 will be donated to the Internet Security Research Group.
The seed generation process in the article can be reproduced with timestamps from 1997 to 1998 and lrand48, providing a concrete explanation for the long-standing speculation about the origin of the NIST curve parameters.