encryption migration documentation hard to understand

[rolandu]

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!

[joshtrichards]

Related: #5282