Proton launches privacy-respecting encrypted AI assistant Lumo
Proton has launched a new tool called Lumo, offering a privacy-first AI assistant that does not log user conversations and doesn’t use their prompts for training.
Proton is a Swiss company behind proven privacy and security tools and services, including Proton Mail, Proton VPN, and Proton Drive. In June 2024, it transitioned to a non-profit structure, putting user privacy over profits.
The introduction of Lumo aligns with this mission, as Proton claims this AI tool is designed to provide help without tracking users, retaining or sharing their data, and hiding risky functions in closed-source code.
Instead, Lumo is based on open-source large language models (LLMs) and utilizes Proton’s open-source encryption scheme. Proton also released the tool’s complete source code, so it’s fully transparent to the community.
Lumo’s default setting is not to search online, delete all chats upon closing, and not store conversations on the server-side.
“Other AI companies keep a record of all your conversations on their servers, leaving this information vulnerable to data leaks or exploitation for profit,” reads the announcement.
“Lumo doesn’t keep any logs of your conversations server side, and any chats you save can only be decrypted on your device.”
Lumo’s interface resembles those of mainstream LLM services, while the tool supports file uploads with full encryption support.

Source: Proton
For ultimate security, direct uploads from Proton Drive are also supported.

Source: Proton
Lumo’s infrastructure is located in Europe, where the GDPR applies, so no sensitive data is transmitted to jurisdictions with weaker data protection regulations.
Lumo is available at lumo.proton.me or as an app for Android and iOS devices.

Source: Proton
The service is offered via three account tiers, summarized as follows:
- Guest: No need for a Proton account, but limited to a certain number of questions weekly. Does not offer the option to retain conversations.
- Free: Proton account required. Adds file uploads, increases question number limits, and offers basic chat history encryption.
- Plus: Costs $12.99/month. Unlocks all features, including unlimited chats, extended encrypted chat history, unlimited favorite chats, and the ability to upload multiple large files.
At launch, Lumo supports and responds in English, French, German, Spanish, and Italian, with additional languages to be added gradually.
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