Anthropics' Claude cracks a 25-year-old NSA cryptography mystery in under 30 minutes
Quick Answer
Anthropic's AI model Claude solved a 25-year-old NSA cryptography mystery in under 30 minutes, revealing that the seeds for ECDSA curves were generated using 'lrand48' with a Unix timestamp.
Quick Take
This discovery reduces concerns about potential backdoors and the company is donating the $36,864 bounty to the Internet Security Research Group.
Key Points
- Claude identified the ECDSA seed generation method using 'lrand48' random number generator.
- The seeds were initialized with Unix timestamps from May 1997 to April 1998.
- The discovery suggests a lower likelihood of deliberate backdoors in NSA's cryptography.
- Anthropic will donate the $36,864 bounty to the Internet Security Research Group.
- The mystery had previously attracted amateur sleuths and a bounty for its resolution.
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~1 min read
Oct 17, 2026
Anthropic's AI Claude has solved a 25-year-old cryptography mystery. NIST standardized several curves in the ECDSA standard, the most widely used framework for elliptic-curve digital signatures, back in 2000. The NSA had supplied the seeds, the starting values used to generate the curve parameters, with zero explanation. No one knew how they were created, and that fueled suspicion of possible backdoors. The mystery even attracted a bounty and amateur sleuthing efforts. The late NSA employee Jerry Solinas had suggested the seeds were a hash of a humorous phrase, but that turned out to be wrong.
Claude cracked it in under 30 minutes. The seeds came from "lrand48," a simple C random number generator, initialized with a Unix timestamp between May 1997 and April 1998. Claude spotted the pattern because "lrand48" only outputs 31 bits, and the top bits in some seeds were systematically zero. According to Anthropic, this makes deliberate backdoors less likely. Anthropic is donating the $36,864 bounty to the Internet Security Research Group.
— Originally published at the-decoder.com
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