# OpenAI — Doppel’s AI defense system stops attacks before they spread

- Company: OpenAI (openai.com)
- Announced: 2025-10-28T10:00:00+00:00
- Subject: GPT / ChatGPT / API
- Models affected: GPT-5
- Source: https://openai.com/index/doppel
- Record: https://forck.live/items/406-doppel-s-ai-defense-system-stops-attacks-before-they-spread

Doppel uses GPT-5 and reinforcement fine-tuning to stop deepfake and impersonation attacks, reducing analyst workloads by 80% and response times from hours to minutes.

## Evidence

Verbatim from https://openai.com/index/doppel:

> Doppel uses GPT-5 and reinforcement fine-tuning to stop deepfake and impersonation attacks, cutting analyst workloads by 80% and reducing response times from hours to minutes.

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Record: https://forck.live/items/406-doppel-s-ai-defense-system-stops-attacks-before-they-spread
Catalogue: https://forck.live/llms.txt
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