Direct discovery · Computer science · Mathematics

Claude-assisted cryptanalysis weakens HAWK and reduced-round AES

New cryptanalytic attacks that reduce HAWK's effective key strength and improve attacks on a seven-round AES variant.

Summary

Anthropic reports that Claude Mythos Preview helped produce an improved key-recovery attack on the NIST post-quantum signature candidate HAWK and a faster attack on a reduced-round AES variant. The company published technical papers and code, coordinated disclosure with HAWK's authors and NIST, and says it consulted academic cryptographers to confirm the findings.

AI role

Claude Mythos Preview performed literature review, mathematical reasoning, computational experiments, and verification-pipeline implementation in agentic cryptanalysis workflows with limited human guidance.

Narrative role

This is a concrete theoretical-computer-science output rather than a benchmark score: an agentic model workflow produced technically specified cryptanalytic advances on actively reviewed algorithms, illustrating both research acceleration potential and dual-use pressure.

Caveat

The evidence is a company release and its linked papers rather than peer review. Neither result breaks deployed full AES; HAWK remains a candidate scheme, and the reported external checking is described by Anthropic.

Event

Date: 2026-07-28
Timeline role: Notable
Progress relevance: Scientific output
Validation: Externally checked

Evidence

Frontier lab announcement · Paper

Observed metrics

HAWK attack effort: about 60 hours; Anthropic reports the semi-autonomous discovery, development, and verification time for the HAWK attack.
HAWK-256 key-recovery cost: 2^38 versus 2^64; The reported improved attack lowers the expected work factor for the smallest HAWK parameter set.
reduced-round AES attack speedup: 200-800×; Anthropic reports the improvement over prior attacks on a seven-round AES variant, not full AES.

Source: Anthropic ↗