FrontierJuly 28, 2026via The Decoder
Anthropic says its Mythos model found vulnerabilities in cryptographic algorithms that secure the internet
Why it matters
Anthropic's Mythos model demonstrated a new frontier capability: discovering cryptographic vulnerabilities faster and cheaper than expert human review. This isn't a theoretical benchmark—it's a real-world application showing AI reasoning at a level that challenges decades-old security assumptions, with direct implications for how enterprises think about AI risk and cryptographic infrastructure planning.
Key signals
- Mythos found vulnerability in HAWK post-quantum signature scheme
- Human experts reviewed same scheme for 2+ years without finding it
- AI discovered vulnerability in 60 hours at $100,000 API cost
- Findings don't affect systems currently in use
- Represents new reasoning/vulnerability-discovery capability for large models
- Raises questions about AI and cryptographic security assumptions
The hook
60 hours. $100k. Claude Mythos just found what human cryptographers missed for 2+ years—and it's forcing a reckoning on internet security.
Anthropic's Claude Mythos Preview found weaknesses in key cryptographic algorithms, including a better attack on HAWK, a post-quantum signature scheme that human experts had reviewed for more than two years. The model found it in just 60 hours at an API cost of about $100,000. The findings don't aff…