The NIST Elliptic Curves Seeds Bounty Has Been Claimed

A team from Anthropic solved a 26-year mystery by determining that the seeds for NIST's elliptic curves were generated using the POSIX drand48 random number generator seeded with Unix timestamps in 1997-98, rather than hashed English sentences as previously believed. The team claimed a bounty announced three years earlier and donated the $12,288 prize to ISRG/Let's Encrypt, tripling its value to $36,864. While the basic generation method is now understood, one undocumented selection criterion remains unexplained, leaving roughly twice as many valid seeds as were actually published.