Claude cracks a 25-year NSA mystery in 30 minutes

An internal Anthropic research model has solved a cryptography mystery that had stood for 25 years, tracing the unexplained seed numbers behind the NSA-supplied NIST elliptic curves to lrand48, an ordinary random-number generator in older C libraries, seeded with timestamps from 1997 and 1998. The model produced the answer in less than 30 minutes, without being told the older theory that the seeds came from a forgotten humorous phrase.

For the widely used P-256 curve, Claude reproduced the published seed as the 1,842nd candidate in the generated sequence. Anthropic says the reproducible result makes a deliberately hidden backdoor much less likely and that no action is needed by users of the curves, though it cannot explain why some usable candidates were skipped. Bitcoin was unaffected because it uses secp256k1, a simpler curve with little room to conceal a weakness. The $36,864 bounty will be donated to the Internet Security Research Group.