news-tldr.com

The important facts, the open questions, and the sources — without the churn.

← Latest briefing

Technology

Claude reportedly traces NIST elliptic curve seeds to a C library generator

Hacker News reports that Anthropic says Claude traced NIST curve seeds to a timestamp-seeded C library generator, not a hash.

Updated Oct 16, 2026 · 20:29 UTC1 reports

The short version

  • Anthropic says Claude traced NIST P-192 through P-521 seeds to lrand48 output seeded with Unix timestamps.[Hacker News]
  • Anthropic says the prime-curve seeds correspond to clock values from May 1997 to April 1998, and the binary-curve values may reflect a halved clock.[Hacker News]
  • Anthropic says this reduces concerns about intentional backdoors, but base points for P-224, P-256, P-384 and P-521 remain unexplained.[Hacker News]

Key facts

  • Claude identified the origins of the NIST P-192, P-224, P-256, P-384 and P-521 seeds, which were outputs of the C library's lrand48 generator seeded with a Unix timestamp.[Hacker News]
  • For P-256, the published seed corresponds to the 1842nd candidate produced by the generator in that run.[Hacker News]
  • Recovered generator states for the prime-curve seeds correspond to Unix timestamps between May 1997 and April 1998.[Hacker News]
  • Base points for P-192 and five ANSI X9.62 example curves, generated in May 1997, came from the random number generator in Arjen Lenstra's FreeLIP package.[Hacker News]
  • Anthropic says the finding is not a cryptographic break, new attack, or weakness in the ECDSA curves.[Hacker News]
  • Anthropic is donating a $36,864 bounty for finding the seeds to the Internet Security Research Group.[Hacker News]

What remains uncertain

  • Base points for P-224, P-256, P-384 and P-521 remain unexplained, and the generation method for NIST binary curve base points is unknown.[Hacker News]
  • Some potentially valid candidate curves were skipped during seed selection, and the reporting does not fully explain this.[Hacker News]
  • The binary-curve timestamp mapping suggests the program may have halved the clock, which is a suggestion rather than a confirmed finding.[Hacker News]
  • Only one outlet, Hacker News, is reporting these claims, which originate from Anthropic's announcement and have not been independently verified in the provided reporting.[Hacker News]

Sources

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.