Doppel is an AI defense system that uses a combination of GPT-5 and reinforcement learning to detect and prevent deepfake and impersonation attacks. According to its creators, Doppel can reduce analyst workloads by 80% and cut response times from hours to minutes. The exact details of how Doppel works are not publicly available, but it is claimed to be effective in stopping the spread of such attacks. --- Why it matters: This matters because deepfake and impersonation attacks pose a significant threat to online security, and tools like Doppel can help mitigate this risk by providing faster and more efficient detection and response capabilities. Source: https://openai.com/index/doppel