AIBRIEF
A prior Type0 piece reported Anthropic's model cut attack costs on HAWK, a third round NIST post quantum candidate, and recovered a key byte on a 7 round variant of AES. Outside cryptographers have since confirmed the AES result.
Anthropic on 2026-07-28 published two cryptanalytic results from a Claude model: cost drops against HAWK and reduced-round attacks on AES. A prior Type0 piece covered that announcement. This is a development update on what has and has not been independently confirmed since.
The AES result has outside validation. Milad Nasr and Nicholas Carlini's paper describes an algebraic Möbius bridge that eliminates one of nine guessed key bytes on a 7-round variant of AES, extending a 2013 Derbez-Fouque-Jean algorithm. Outside cryptographers have reportedly confirmed the result, according to NewsBytesApp.
The HAWK result has not been independently confirmed in public reporting. Zygimantas Straznickas and Stephen A. Weis's paper lowered the key-recovery cost in the gate-count model of [AGPS20] from 2^150 to 2^108 — a reduction on a cipher not yet in production standards and a third-round NIST post-quantum candidate. No outside cryptographer has publicly validated that cost drop in any reporting to date.
The open question, as the prior piece noted, is whether the same automation produces published cryptanalysis on the round counts and parameter sets the standards bodies actually use.