I am not at all an #Apple person. Can someone tell me how I can verify that a Time Machine backup on a NAS has been encrypted on the client side (other than via the Time Machine GUI on the client machine)? I would assume that if I have access to the NAS volume itself (which I do) it should be possible to verify that it's not plaintext (even if I can't verify the specific type of encryption or that it's not corrupted).
@internic You could try and look at saved data to see if you can read any of the files. When I look at my time machine backup I can read individual files. Did you specify a password when you created a backup?
@Tyrion1803 I can read the XML files (e.g. .plist files) at the top of the file hierarchy, but below that are a bunch of opaquely named files in the mapped and bands subdirectories, which I would assume are mostly binary. The only thing I could think to do was try to run 'strings' on some of the files, but given that it's over 1 TB of data I'd rather not try to sift through it for text.
The problem here is that I've never gotten to compare an encrypted Time Machine backup and a non-encrypted one, so I don't know how they're expected to differ.
To your other question, the person who made the backup (not me, again, I'm not a Mac user) doesn't know. But that's why I was thinking "surely there's a way to tell whether it's plaintext just by looking at the sparse bundle," which I imagine is true but I don't know what to expect. Presumably, even if it's encrypted there's may be some plaintext metadata at the top level.
@internic What if you create a file say on the desktop and then back it up. Navigate to the same spot on the folder structure of the backup (if you can) and see if the file is there to simply read it.
@Tyrion1803 Other than metadata files at the top of the file hierarchy (the plists, lock file, etc.), everything else under the mapped and bands is an file with an opaque 3-hex-character name unrelated to the actual names of actual files on the system being backed up. If you see normally-named files on yours, I guess maybe this is the sign I was looking for that things are encrypted.
