Mythos attack on 3rd-round PQC algorithm candidate puts it out of commission

Anthropic said its Mythos security model uncovered a weakness in HAWK, a post-quantum digital signature scheme under NIST review.

The attack worked on weakened test instances and reduced the scheme’s effective key strength, but it did not break deployed cryptography.

Still, HAWK’s developer withdrew it from consideration, ending its run as a candidate for a future U.S. standard.

The result highlights how AI tools may help expose flaws in advanced cryptographic designs and shape post-quantum selection.