Anthropic's Claude solves a 25-year mystery over the origins of widely used encryption curves in under 30 minutes
An internal Claude model traced the unexplained seeds behind the NIST elliptic curves used across the internet to an ordinary 1990s random-number generator seeded with timestamps from 1997 and 1998. The reproducible result makes the long-rumoured idea of a deliberate NSA backdoor much less plausible.
One of cryptography's longest-running puzzles has been closed by an AI model in less than half an hour. Anthropic said on 16 October that an internal version of Claude identified how the seeds behind the NIST elliptic curves — the ECDSA standard adopted in 2000 and still used to secure connections, signatures and cryptocurrencies across the internet — were originally generated. The US National Security Agency supplied those seed values a quarter of a century ago with no explanation, and their unexplained origin fuelled years of speculation that the curves might have been chosen to hide a deliberate weakness.
Claude's answer turned out to be mundane, which is exactly why it matters. The seeds were not produced by hashing a secret phrase, as rumour had it, but by the old C library random-number generator lrand48, initialised with Unix timestamps between May 1997 and April 1998. The model spotted the generator's fingerprint in the pattern of the published bits, recovered its internal state — using a textbook lattice technique for the harder prime-curve cases — and showed that each recovered state regenerates the full 160-bit published seed. Anthropic published code that lets anyone reproduce the seeds for curves including P-192, P-224, P-256, P-384 and P-521.
This is not a break of ECDSA and requires no action from anyone using the curves, Anthropic stresses. If anything, it points the other way: seeds generated by a common generator started from the clock leave far less room for someone to have searched for secretly weakened parameters, so the finding makes a deliberate backdoor considerably less plausible. Claude also explained the origin of some of the curves' base points, which came from another period software library, although the base points of P-224, P-256, P-384 and P-521 and one binary-curve seed, B-163, remain unexplained.
The $36,864 bounty attached to the mystery will be donated to the Internet Security Research Group, the non-profit behind Let's Encrypt. Beyond the cryptography itself, the episode is a concrete example of an AI system doing open-ended investigative research — forming a hypothesis about how 1990s software must have worked, testing it computationally and verifying the result exactly — on a question that human specialists had left unsolved for 25 years.
Source: Anthropic