Anthropic’s latest crypto attacks target HAWK and reduced-round AES, not deployed standards

matthew_d_green · x · 2026-07-29

Anthropic’s new cryptanalysis outputs target HAWK and reduced-round AES

Matthew Green summarizes Anthropic’s latest research results from Claude Mythos: one attack targets HAWK, a proposed post-quantum signature scheme, and the other improves an attack on reduced-round AES.

He stresses that the HAWK result does not break a deployed standard: HAWK is still a proposed scheme and the attack remains exponential-time, though it roughly halves the effective security margin. The AES result is a separate, different-quality cryptanalysis effort. His post frames both findings as interesting research, but not evidence that real-world deployed crypto is suddenly broken.

Related event: Claude Discovers New Cryptographic Weaknesses in HAWK and Simplified AES(35 posts)→

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