Anthropic said on Oct. 16 that Claude had helped reconstruct the public seed behind P-256, a cryptographic curve supported for Ethereum passkey signing. Anthropic says the finding makes deliberate backdoors less plausible and requires no user action. The public seed is separate from private signing credentials. The published recipe reproduces the P-256 seed at candidate 1,842, but Anthropic reports that candidate 876 also produced a suitable curve. The selection criteria, number of generation runs and origin of P-256's base point remain unresolved.