What a vault is

A vault is a folder in Files whose contents are encrypted in your browser before anything is uploaded, under a key that was generated on your device and that we have never held. The files and their names are ciphertext to us. We cannot decrypt them for you, for a colleague, or for anybody who asks us to, including in response to a legal request.

That is not a setting on a file. It is what a folder is: a vault is made empty, and everything that goes into it is encrypted on the way in. The exact same guarantee is written into the privacy policy and the terms, in the same words, because it is the one claim in Nemi that people act on.

What we can and cannot see#

What stops working inside a vault#

Everything Nemi does by reading a file happens on our machines, and a vault file cannot be read there. So none of it runs, and each one tells you why rather than failing quietly:

• Thumbnails and the previews we render. A vault file is previewed by your own browser or not at all.
• Converting and compressing. Download the file, convert it, and add the result back.
• Virus scanning. Scanning means reading, so vault files are not scanned. Only your own devices ever see the contents.
• Zip downloads. A folder of vault files cannot be zipped on our side, and a zip of a mixed selection says how many files it left out.
• Share links. A link would hand somebody bytes nobody can open, so access is given per person instead.
• Search. Vault file names and contents only exist decrypted in your browser, so nothing in a vault is findable from the search box.
• Renaming a file from the ordinary file list, copying it, and moving it out of the vault. The name is encrypted, and outside the vault nothing holds the key to the file.

What does work#

• Adding files, which are encrypted on your device before a byte leaves it.
• Downloading, which decrypts in your browser and saves the file under its real name.
• Previewing what your own browser can draw: photos, video, audio, PDFs, plain text, Markdown and CSV. Anything else is downloaded instead. The preview is labelled "Decrypted in your browser" because that is exactly what happened.
• Deleting a file, and giving another person access.

Unlocking lasts for the tab#

You unlock your vault key once with a passkey or a passphrase, then open the vault itself. Both are held in that tab and nowhere else. Closing the tab locks everything, and so does a refresh. There is a Lock button to do it on purpose.

That is deliberate and it is not going to change. If the key were saved on the computer, the vault would unlock itself for whoever opens the laptop next, and "we cannot read your vault" would quietly become a much smaller promise.

Questions people ask before they start#