# Linear Congruential Generator

The provenance of the NIST standard elliptic-curve “seeds” had been unexplained since the NSA supplied them without justification, and the community long suspected possible backdoors. An internal Anthropic research model, Claude, found in under half an hour that the seeds for P-192, P-224, P-256, P-384 and P-521 are not the output of any hash algorithm but of the 1990s C library generator lrand48 seeded with a Unix timestamp, with the P-256 seed appearing at iteration 1842. This is not an attack or a weakness in ECDSA; it makes deliberate backdoors much less plausible, while the B-163 seed and the base points of P-224, P-256, P-384 and P-521 remain unexplained.

The provenance of the NIST standard elliptic-curve “seeds” had been unexplained since the NSA supplied them without justification, and the community long suspected possible backdoors. An internal Anthropic research model, Claude, found in under half an hour that the seeds for P-192, P-224, P-256, P-384 and P-521 are not the output of any hash algorithm but of the 1990s C library generator lrand48 seeded with a Unix timestamp, with the P-256 seed appearing at iteration 1842. This is not an attack or a weakness in ECDSA; it makes deliberate backdoors much less plausible, while the B-163 seed and the base points of P-224, P-256, P-384 and P-521 remain unexplained.