A rueful joke about Claude followed Anthropic’s report on ECDSA curve origins. The user shared an image and quipped that Claude was “throwing shade at us.” Anthropic’s Oct. 16 report says an internal research model recovered the origins of several NIST curve seeds in under half an hour.
Those seeds are published parameters used to define standardized elliptic curves. According to Anthropic, the seeds for P-192, P-224, P-256, P-384 and P-521 came from the C library’s lrand48 pseudorandom-number generator initialized with Unix timestamps. That differs from an earlier lead involving a hashed humorous phrase.
The report describes Claude searching for signatures of older random-number generators, then reconstructing their internal states. For the prime-curve seeds, it used lattice-based methods to recover the state from partial output. Anthropic supplies code to reproduce the seeds.
Anthropic stresses that this is not a cryptographic break, new attack or newly discovered weakness in ECDSA. Questions remain: the B-163 seed and several base-point origins are unexplained, and the researchers do not know why some viable candidate curves were skipped.
