Encrypted AI chat, explained honestly

The four kinds of encryption

In transit (TLS) (What it protects against: Someone on your network reading traffic; Can the company read your chats?: Yes). At rest (What it protects against: A stolen disk or database backup; Can the company read your chats?: Yes, through the app). End-to-end or zero-access (What it protects against: The company itself reading stored chats; Can the company read your chats?: No, keys stay with you). Confidential computing (TEE) (What it protects against: The host reading prompts while the model runs; Can the company read your chats?: Not during inference, if attested). There is a catch that no encryption removes. To answer you, a model has to read your prompt in plain text. End-to-end encryption protects what is stored. It only protects what is processed when the model itself runs inside verified hardware.

Where Quad sits

Quad encrypts chats and files in transit and at rest. Quad is not end-to-end or zero-access encrypted. It stores your history so you can open it on the web, your computer and your phone, and so Quad can search your own chats and files when you ask. Instead, Quad limits who keeps your data. 47 of 51 chat models run on the Private Lane, where the provider is under a Zero Data Retention agreement and keeps nothing after answering. Quad never trains on your chats or files and never sells them, and you can export or delete them any time. We would rather say this plainly than let the word encrypted imply more than it means.

Who offers the stronger guarantees

Based on each product's own pages, checked October 14, 2026. Proton Lumo describes zero-access encryption for stored chats. See the Lumo comparison. Venice offers end-to-end and hardware-verified inference on paid plans. See the Venice comparison. Confer and Maple describe end-to-end encrypted chat built on confidential computing, with open models. Local apps such as Ollama and LM Studio keep everything on your own computer. These designs usually trade capability for the guarantee: fewer or smaller models, history that does not sync, or no documents and agents. Choose by what you are protecting against.

Six questions to ask any AI app

Who holds the keys to your stored chats, you or the company? Does your history sync across devices? If it does, the service can usually decrypt it. Which company runs the model, and does it keep prompts after answering? Are chats used for training, and is that the default or a setting? Can staff or contractors review chats, and when? Is there a published list of the companies that process your data, and can you export and delete everything yourself? Quad's answers are on the security page, the subprocessor list and the private AI chat page.

How to choose

If the company must be unable to read stored chats, choose a zero-access or end-to-end product. If nothing may leave your computer, run a local model. If you want the frontier models with no training and no provider retention, and synced history is fine, Quad fits. Whatever you choose, keep secrets and regulated data out of tools your contract does not allow.

Frequently asked questions

Is Quad end-to-end encrypted?

No. Quad encrypts chats and files in transit and at rest, and it stores history so it can sync it across devices. It does not claim end-to-end or zero-access encryption.

Can an AI chat be fully end-to-end encrypted?

Only partly. The model must read your prompt to answer, so the strongest designs also run the model in verified confidential hardware. Most of them use open models rather than GPT, Claude or Gemini.

What does Zero Data Retention mean?

It means the model provider does not store your prompts or responses after it answers. In Quad, Private Lane models run under a Zero Data Retention agreement.

Can Quad employees read my chats?

Your chats are stored encrypted to provide the product, with access restricted by role. Quad never trains on them, never sells them and never shares them with advertisers.