Encrypt Filenames SSE

[Toorero]

Currently, if you enable server-side encryption (SSE) and I suspect by extend end-to-end encryption (E2EE) names of files are not encrypted. I think this is a major overside and should be fixed because filenames can give a lot of information about the content stored in a file. File names (and even folder names) can contain private and/or personal information, like names of persons, places bank accounts present, etc. Even highly sensitive data like gender or sexual orientation can be exposed via unencrypted filenames

This fact is also stated in the official manual, so this is obviously "intended behaviour" but severely limits the application of SSE impov.

[Toorero]

Related to #5553

[Toorero]

Server-side-encryption in the current state fails the purpose to "protect users’ files on remote storage" because crucial information is exposed via the non-encrypted paths. As long as the feature is not implemented, this critical issue with SSE should be highlighted as a red warning banner at the top of the official documentation here I think.

[Juusttiinn]

It's hard to believe that this serious issue has not been fixed by the developers after EIGHT years. While an unencrypted directory structure isn't perfect, it's an acceptable compromise. However, unencrypted filenames shouldn't be considered an acceptable or expected behavior; it's a bug.

The necessity for this feature has been clearly articulated by others. Furthermore, there are mature, open-source implementations for filename encryption available, so performance and development difficulty shouldn't be an issue.

As Nextcloud is the leading open-source cloud storage solution, I hope the day when filename encryption is implemented comes sooner rather than later.

[hendricksond]

For external storage, I'd even be happy with something like UUID (or otherwise tokenized) filenames on the external filesystem, with the actual filename/path stored in nextcloud's database. I just can't have filenames/directories with potential PII in them on external systems.