Hoppa yfir í aðalefni

"Hide Download" / Secure View Is Not a Security Boundary

Nextcloud offers a Secure View option (sometimes labeled "hide download" or "view only") when creating a share. It looks like a permission control, but it only removes the download button from Nextcloud's own web interface.

Why it doesn't actually stop anyone​

Secure View is a UI-layer restriction, not a data-layer one. The file itself is unchanged — anyone with access to the share can typically still retrieve the original through one of Nextcloud's other access paths, such as the WebDAV interface (see Mounting Nextcloud as a Local Drive), the desktop sync client, or the mobile app. None of these are guaranteed to respect the "hide download" flag the way the web UI does. Screenshots and photos of the screen are, of course, always possible regardless of any technical control.

Do not rely on Secure View for sensitive data

If a dataset genuinely needs to be technically prevented from leaving a controlled environment — not just discouraged from leaving it — Secure View is the wrong tool for it.

What actually is reliable​

Two share-level restrictions genuinely constrain what a recipient can do, because they're enforced by Nextcloud's own permission system rather than by hiding a UI button:

  • Disable resharing — the recipient cannot create a new share from the files inside, so access can't silently spread beyond who you gave it to.
  • Disable desktop sync — the recipient's desktop client cannot pull the folder down to their machine, which limits copies to Nextcloud's own web session rather than every device the recipient owns.

Neither of these prevents someone from downloading and keeping a copy through the web UI — they reduce the number of places a copy can end up, not eliminate copies entirely.

Needs confirmation: the exact menu path/toggle labels for disabling resharing and desktop sync in our current Nextcloud version, so this page can show the real UI instead of describing it abstractly.

For data that needs a real security boundary​

If a project's data governance requirements need an actual enforced boundary — not just a UI hint — that requirement belongs in the HPC-side data enclave, not Nextcloud. Contact irei@hi.is to discuss what your project needs before choosing where the data lives.