Privacy-focused technology firm Proton has launched Lumo, a new AI chatbot designed with a core principle: keeping user conversations confidential. As AI becomes increasingly integral to daily interactions, concerns have grown over data privacy especially when conventional platforms analyze or retain user inputs.

End-to-End Encryption & Zero-Access Design

Lumo is built on a foundation of end-to-end encryption and zero-access architecture. Conversations are encrypted on the user’s device and can only be decrypted by the owner neither Proton nor any third party can access or log the content. A “ghost mode” further enhances privacy by ensuring chats vanish permanently once closed.

Utilizes Privacy-Friendly Open‑Source Models

Engineered for transparency, Lumo runs on reputable open-source models like Mistral Nemo, Mistral Small 3, Nvidia OpenHands 32B, and OLMO 2 32B. These models are hosted in Proton-owned European data centres, ensuring that user data remains isolated and never reused to train AI systems. Web search functionality is available but only when explicitly enabled by the user.

Practical Features Without Data Compromise

Lumo supports common AI tasks: rewriting emails, summarizing documents, generating code, and answering questions. It also integrates with Proton Drive, allowing encrypted files to be analyzed in-chat while preserving security. The service is accessible via browser or iOS/Android apps.

  • Free users receive up to 100 chats per week
  • Anonymous users can access up to 25 chats
  • Lumo Plus ($12.99/month) unlocks unlimited chats, larger file uploads, and extended chat history

A Clear Alternative to Big Tech AI

“What sets Lumo apart is its trust-first architecture,” says Proton CEO Andy Yen. Unlike many AI platforms that utilize user data for training or analytics, Lumo never stores or shares chat data, protecting users from surveillance or data monetization. Its design prioritizes individual privacy over commercial leverage, positioning it as a unique, secure option in the AI landscape.

Final Thoughts

With Lumo’s debut, Proton challenges conventional AI norms by offering a fully encrypted, no-logs chatbot experience using open-source models. Ideal for privacy-conscious users legal professionals, journalists, or anyone wary of data harvesting it’s a significant move toward sheltered AI communication.

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