encryption migration documentation hard to understand

Nextcloud Server Version: 21.0.1 (but the issue already appeared at 20.x)

I am getting the warning "The old server-side-encryption format is enabled. We recommend disabling this. For more details see the documentation." (linking to <https//docs.nextcloud.com/server/21/admin_manual/configuration_files/encryption_migration.html>)

I find the page very hard to understand and I believe the reason is that there are many different names used for encryption throughout the documentation:

• server-side encryption
• default encryption (the module implementing server-side encryption)
• legacy encryption
• "the old server-side-encryption format" (probably same as "legacy encryption")

In a forum I was pointed to the encryption blog post introducing end-to-end-encryption, which is yet another kind of encryption. The blog post added to my confusion somewhat.

Another aspect I find difficult to understand is that there is no opposite of "legacy" in the text. I would expect a text to say that there is "legacy" and "modern" or "version 1" and "version 2". It is unclear what I am upgrading towards if I turn off legacy.

I believe one of the following is true (or maybe both):

• server-side = default = legacy encryption and it will go away entirely, users are asked to disable server-side and use end-to-end-encryption in the future.
• servers-side = default encryption and there is a new version of "default encryption" module which uses a new format and "legacy encryption" is the format of the old version of "default encryption". So this is simply an upgrade.

If the latter is true, I would recommend to re-phrase the documentation towards explaining that "default encryption needs to be upgraded" instead of introducing the term "legacy encryption" which is not used anywhere else in the documentation.

I would be grateful if someone could explain a bit more in detail what the warning means and what needs to be done.

Thanks!

Start with the encryption migration page linked in the warning and compare its terminology with the linked Nextcloud encryption blog post. Confirm how server-side, default, legacy, and end-to-end encryption relate, then revise the documentation so the migration target and required user actions are unambiguous.