backupencryptionsmbtime-machine
I see other questions regarding encrypting Time Machine backups to external disks, like this one:
There it says the entire disk is encrypted.
But for a network disk, I find it hard to believe that Time Machine can encrypt the disk. For example, is remote encryption of an entire disk possible via SMB?
Of course, Time Machine still supports encryption to a network drive, so then what exactly is it doing?
It encrypts the partition that you use for Time Machine, which likely means the entire disk. If you partition the drive the other partitions will not be encrypted and should mount (I have not tested this).
You can see that "Time Machine" is encrypted, but "Other Backups" is not.
No, the backups will not be encrypted automatically, but it's very easy to enable for directly attached disks. Just check "Encrypt Backup Disk" in the Time Machine disk selection settings.
If you're backing up to another Mac, you can use Disk Utility on that Mac to erase non-boot drives and put an encrypted partition on them:
Best Answer
Neither the remote disk nor the remote volume is encrypted by Time Machine. Instead a special "sparse bundle (disk image)" ("backupbundle" for Catalina) is created on the network drive. In fact it's no uniform disk image file like a dmg but a special folder containing sub-folders and config/log files.
The content of the source volume(s) is saved as AES-128-encrypted band (or chunk) files in the bands folder.
The password is merged into a special file named token in the backupbundle.
The remote disk or volume could be encrypted independently though. This depends on the (TM-)server config.