--- format: "aidr-story-markdown/v1" id: "b8ab495a8a07d587d47579eb4303a1d1c1d17d9b5700a3eaf44508669619d2a2" canonical_url: "https://aidr.today/b8ab495a?lang=en" title: "Anthropic says new measures like preserved thinking in Fable 5.1 and Opus 5.5 have reduced data harvesting through distillation attacks by about 90% to 99% (Anthropic)" lang: "en" requested_lang: "en" available_langs: ["en","vi"] translation_fallback: null fallback_fields: [] published_at: "2026-10-13T03:45:01.000Z" category: "Research" topics: ["anthropic","safety","llm"] source_urls: ["https://www.techmeme.com/261012/p46","https://x.com/AnthropicAI/status/2109795898909950247","https://x.com/Hesamation/status/2109800675664101749","https://x.com/JaguarAnalytics/status/2109811964884955542","https://x.com/edzitron/status/2109844566467850242","https://x.com/DavidSacks/status/2109849209742450696","https://x.com/kimmonismus/status/2109935284406157790","https://x.com/mark_k/status/2109981857517281395"] summary: "Anthropic says new measures like preserved thinking in Fable 5.1 and Opus 5.5 have reduced data harvesting through distillation attacks by about 90% to 99%. These methods have been used to reduce the effectiveness of distillation attacks on Claude in recent months." --- # Anthropic says new measures like preserved thinking in Fable 5\.1 and Opus 5\.5 have reduced data harvesting through distillation attacks by about 90% to 99% \(Anthropic\) > [Open the canonical story]() **Published:** 2026-10-13T03:45:01.000Z **Category:** Research **Topics:** anthropic, safety, llm ## Summary Anthropic says new measures like preserved thinking in Fable 5\.1 and Opus 5\.5 have reduced data harvesting through distillation attacks by about 90% to 99%\. These methods have been used to reduce the effectiveness of distillation attacks on Claude in recent months\. ## Sources - [Story source]() - [Story source]() - [Supporting source]() - [Supporting source]() - [Supporting source]() - [Supporting source]() - [Supporting source]() - [Supporting source]()