tl;dr: Anthropic researchers used Claude to solve a 25-year mystery about the origins of the NIST ECDSA curve seeds, discovering they were generated by the C library's lrand48 PRNG seeded with Unix timestamps from 1997-1998, not from a hashed passphrase as long rumored. Claude recognized the PRNG's signature (zeroed top bits) and used LLL lattice reduction to recover internal states, also identifying the base points for several curves via Arjen Lenstra's FreeLIP generator. The finding isn't a cryptographic break—it actually increases confidence that the curves lack backdoors—and the $36,864 bounty will be donated to the Internet Security Research Group.