Discovering Cryptographic Weaknesses with Claude

anthropic.com
July 28, 2026
18 min read
59/100
Summary
Researchers at Anthropic have utilized Claude Mythos Preview to uncover vulnerabilities in cryptographic algorithms. One attack significantly compromises the HAWK digital signature scheme, while another reveals a new method to exploit round-reduced AES, a widely used symmetric cipher.
Key Takeaways
- Researchers at Anthropic used Claude Mythos Preview to discover improved attacks on cryptographic algorithms, specifically weakening the HAWK digital signature scheme and identifying a new attack on round-reduced AES.
- The attack on HAWK effectively cut its key strength in half within 60 hours of work, despite it being a candidate for post-quantum security.
- Claude Mythos Preview improved the speed of attacks on a weaker version of AES by 200-800 times, showcasing the potential of AI in identifying flaws in cryptographic systems.
- These findings do not currently impact production systems, as HAWK is not deployed and the attack on AES concerns a reduced version of the algorithm.
Coverage & discussions
Hacker News · anthropic.com
Community discussions
Community Sentiment
Positives
- Spending $100k in tokens in a week is an impressive feat even with massive parallelization, showcasing the power of Claude's capabilities in cryptographic research.
- The collaborative approach led to significant breakthroughs in discovering vulnerabilities, highlighting the potential of multi-agent workflows in AI applications.
- The HAWK attack's ability to halve the effective key length is a noteworthy achievement in cryptographic research, raising questions about future standards.
Concerns
- The obsession with 'prompt engineering' feels misguided when the software still struggles to follow instructions effectively, pointing to fundamental limitations in LLMs.
- There's a growing tech aristocracy with access to powerful AI tools that could widen the gap between those who can afford extensive API usage and the average user.
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