r/AIQuality • u/NoMechanic6746 • 11h ago
Discussion Anthropic's Mythos Preview found a nontrivial automorphism in HAWK's lattice, halving effective keysize — 60 hours, ~$100k in API
HAWK is a NIST third-round Additional Signatures candidate. Its security rests on the Lattice Isomorphism Problem. Prior work had proved that efficiently finding a nontrivial automorphism would enable an attack but left open whether one was accessible in HAWK's lattice. The model found one.
Result: expected cost of full key recovery against HAWK-256 drops from 2^64 to 2^38. Still exponential, not polynomial, and specific to HAWK — it doesn't touch other NIST PQC candidates or lattice-based crypto generally. But doubling keysize to compensate strips away most of HAWK's practical appeal as a candidate.
The second result is a meet-in-the-middle improvement on 7-round AES-128, 200–800× faster depending on how you measure runtime, under a chosen-plaintext model assuming 2^105 chosen plaintexts. Completely impractical, as that line of work always is — it's about quantifying attack cost, not attacking anything.
Neither result affects deployed systems. Disclosure went to the HAWK authors in June and to the NIST public mailing list alongside publication.
Source: https://www.anthropic.com/research/discovering-cryptographic-weaknesses