Mythos attack on 3rd-round PQC algorithm candidate puts it out of commission
Ars Technica AI · Dan Goodin · 2026-07-29
Anthropic's AI security model Mythos discovered a critical flaw in HAWK, a quantum-resistant digital signature scheme that had survived two rounds of NIST post-quantum cryptography evaluation, prompting its developers to withdraw it from the standardization process.
Appears in
Extraction
Topics: post-quantum-cryptographyai-cryptanalysisnist-pqccryptography-security
Claims
- Anthropic's AI security model Mythos found a flaw in HAWK that rendered the algorithm broken.
- HAWK is a digital signature scheme designed to resist quantum computer attacks and had passed two rounds of NIST PQC evaluation before the flaw was uncovered.
- Following Anthropic's public announcement of Mythos's findings, HAWK's developer withdrew the algorithm from NIST's standardization process.
Key quotes
A quantum-resistant cryptography algorithm that was under consideration as an official US standard has been taken out of the running after an Anthropic security model helped find a flaw that rendered it broken.
HAWK had survived two rounds of testing by NIST for evaluating the security of PQC algorithms through widespread testing.