Claude unpicks an NSA mystery behind Ethereum passkey security
Anthropic’s timestamp recipe reconstructs P-256’s public seed, adding provenance evidence while leaving selection criteria and base-point origins unexplained. Read the full story on CryptoSlateUnderstand the crypto stories that matter and what to watch next. Get The Catalyst in your inbox
Anthropic said on Oct. 16 that Claude had helped reconstruct the public seed behind P-256, a NIST-standardized cryptographic curve supported for Ethereum passkey signing. The finding gives wallet builders new evidence about a longstanding concern over the curve’s origins.
The seed is a public design input used to derive a coefficient in the curve’s equation. It is separate from the private signing credentials that authorize wallet activity. Anthropic says unexplained seeds supplied by the U.S. National Security Agency had fueled suspicion about deliberately weakened parameters.
The company’s published recipe initializes the old C-library generator lrand48 with the timestamp for Aug. 16, 1997, at 01:52:34 UTC. The generator produces a sequence of candidate seeds. Advancing to candidate 1,842 returns the published P-256 value, providing a repeatable recipe for that public constant.
Anthropic says this makes deliberate backdoors less plausible. It describes no new attack or curve weakness and says users need take no action.
Related ReadingThe Ethereum connection runs through EIP-7951, which specifies verification of signatures using P-256, also called secp256r1. It names Apple Secure Enclave, Android Keystore and FIDO2/WebAuthn devices as relevant hardware. This connects wallet authorization with signing capabilities built into devices and authenticators.