Claude helps factor an 896-bit RSA challenge

Anthropic engineer Stephen A. Weis says Claude helped factor RSA-896, an 896-bit challenge number, using up to 2,048 GPUs and roughly 30 GPU-years of idle compute over 10 days. The published factors make the arithmetic result checkable, but Weis says no new General Number Field Sieve mathematics emerged and RSA-2048 is not meaningfully affected. For security teams, file it beside the archive’s evidence that frontier models can change cyber-engineering economics: migrate any remaining RSA-1024, but do not treat RSA-896 as a modern-key break.