Sharing Files Without Handing the Host the Keys — Proton Drive Links Explained

The email-attachment problem

Email attachments copy a file into at least two inboxes and any server that stored the message. That is fine for a lunch menu. It is a sloppy way to send a passport scan. A cloud share link is better when you can revoke or expire it, and when the host is not keeping a readable copy. Those are separate features. Plenty of clouds offer expiry while still holding keys.

Proton's model is: ciphertext at rest, a link that lets a recipient decrypt in a session Proton describes as not requiring a Proton account for many shares. You still chose to let that person see the file. Forwarding, screenshots, and a shared family PC are outside the cryptography.

From the record

Expiry is for the link you forgot to delete. A password on a different channel is for the inbox you do not fully trust. Neither is for the recipient you should not have trusted.

GUIDEORA sharing rule

Three sharing models, one table

How Proton Drive sharing currently works

Proton's web guide describes two paths: a secure link you can send to anyone, with optional password and expiration; and invite by email with view or edit. Recipients often do not need a Proton account to open a link. Collaborative Docs and Sheets can be edited by people you invite. Permissions are only as good as the account (or the open browser) on the other side.

Set expiry unless the share is truly permanent. Prefer view-only when the other person does not need to change the file. If you must allow edit, remember version history on paid plans can help you roll back — it is not a permissions system.

Mistakes that undo the privacy story

• Putting the link and the password in the same email or Slack thread.
• Leaving expiry on 'never' for a one-time tax document.
• Granting edit to a whole folder because one file needed a comment.
• Sharing from a desktop that is already malware-infected — E2E will encrypt the malware too.
• Assuming 'they don't have Proton' means they cannot screenshot.

A sharing checklist

Before you hit share: is this the smallest file that works? View or edit? Expiry measured in days, not forever? Password on a call or a different messenger? Do you know how to revoke? If any answer is fuzzy, wait.

Use links like tickets, not like tattoos

Proton Drive is a strong fit when you want the host out of the readable copy and you will actually set password and expiry. It is a weak fit when the real need is an open comment thread with a whole company. Choose the tool that matches the social situation, not the encryption slogan.