AI attack slashes HAWK post-quantum signatures (2^64→2^38)

Anthropic’s Claude Mythos Preview reported a new classical-cryptanalysis attack on HAWK post-quantum signatures, despite the scheme passing two years of expert review. The model reportedly found the break in about 60 hours using roughly $100,000 of compute. The key result: the effective work to break HAWK’s smallest parameter set drops from ~2^64 operations to ~2^38. To defend, HAWK would likely need much larger keys, which largely removes the scheme’s practical advantages (including compact signatures that can reduce blockchain fees and space). For traders, the immediate impact is limited. The research does not target the elliptic-curve signatures used by Bitcoin and Ethereum today, and HAWK is not the scheme Bitcoin is moving to under the quantum-address proposal BIP-360. Broader market relevance: the faster pace of classical attacks aligns with the “migration timeline tightening” argument in BIP-361. Separately, the same work improved attacks on a weakened AES variant relevant to wallet-file encryption, while gains against Poseidon (used in many ZK systems) were under ~10x. Overall, this is a watch-item for post-quantum migration planning rather than a direct short-term catalyst for BTC/ETH security.