Anthropic says Claude solved a 25-year-old mystery surrounding the starting values used for several elliptic curves standardized by NIST in 2000. The National Security Agency supplied the seeds without explaining how they were produced, feeding long-running suspicion that the values might hide a deliberate weakness.
Claude linked the seeds to lrand48, a simple random-number generator in the C programming ecosystem, initialized with a Unix timestamp between May 1997 and April 1998. The clue was structural: lrand48 outputs only 31 bits, leaving the highest bits of some generated values consistently zero. According to Anthropic, the model identified the pattern in under 30 minutes.
The finding provides a mundane and reproducible explanation for the numbers, making a deliberately engineered backdoor less likely. It does not prove every historical decision around the curves was benign, but it resolves the specific question of how the unexplained seeds were probably generated.
A public bounty had encouraged researchers to investigate the puzzle, and earlier theories included a claim that the seeds were hashes of a joke phrase. Anthropic is donating the $36,864 bounty to the Internet Security Research Group. The result is a concrete example of an AI system assisting with technical historical analysis rather than merely generating new text.