Claude cracks a 25-year NIST curve seed mystery in under 30 minutes, reviving questions around Bitcoin’s curve choice
Anthropic said on Oct. 17 that its internal model Claude reconstructed the long-unclear seed generation method behind parts of the NIST standard elliptic curves in less than 30 minutes, addressing a question that has lingered in cryptography circles for roughly 25 years. According to the disclosure, the model’s reverse-engineering work suggests the seeds were likely produced with the lrand48 pseudorandom number generator from a 1990s-era C library combined with Unix timestamps, rather than by a complex secret algorithm. The finding matters for crypto because ECDSA underpins digital signatures used across many wallets and identity verification systems. Around 2000, some parameters for NIST standard curves were supplied by the U.S. National Security Agency, while the seed generation process remained opaque, fueling longstanding speculation about possible backdoors. The report also draws a contrast with Bitcoin, where Satoshi Nakamoto chose the secp256k1 curve instead of the NIST curves commonly used elsewhere. Anthropic’s disclosure does not say ECDSA has been broken, and it does not claim any new mathematical weakness has been found in the related curves. Reconstructing how some parameters were generated may help reassess backdoor concerns, but it does not prove that every implementation is risk-free. The episode also points to a broader use for AI in security work: auditing historical cryptographic design choices and testing old assumptions.
