Anthropic LLM Claude Mythos Finds New Cryptanalytic Attacks on HAWK and AES
Anthropic announced on July 28th that its LLM Claude Mythos discovered new cryptanalytic attacks, including a key-recovery attack on the post-quantum signature candidate HAWK and an improved attack on 7-round AES-128. The HAWK attack reduces the estimated security of HAWK-512 from 128 bits to at most 108 bits, though it is not practical; the AES attack poses no threat to full AES. The negative result—no stronger attack found—is considered more significant.
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On July 28th Anthropic announced new cryptanalytic attacks discovered using their LLM Claude Mythos: * A key-recovery attack on HAWK, a post-quantum signature scheme candidate in NIST’s “Additional Digital Signatures” standardization project. Except for the toy version HAWK-256 whose 64-bit security is practically breakable, the **new attack is not practical**. But it's a meaningful break of HAWK’s security, as it reduces the estimated security level of HAWK-512 from its 128-bit target to at most 108 bits and, speculatively, as little as 81 (see Appendix C of the paper.) * An improved key-recovery attack on 7-round AES-128, while the full version does 10 rounds. The attack is , and totally not a surprise, posing **no threat to AES**. But since new cryptanalytic results for AES are rare, this result is noteworthy regardless of the way it was found. The negative result is, perhaps, more significant: Mythos found no stronger attack, let alone against full-round AES. In the AES attack pape