I'm trying to change the Time Machine Backup of a Mac Pro running on Mavericks from unencrypted to encrypted on a Time Capsule. I've already figured out that it isn't possible to convert an existing backup to encrypted. I want to create a new backup to the Time Capsule without deleting the old backup. I just want the old one to sit their unused until I decide to delete it. How can I do this? When I remove the Time Capsule and add it back for an encrypted backup. My only options are "Choose a Different Disk", "Erase Existing Backup" or "Use Unencrypted Backup". I've tried changing the name of the Mac Pro to no avail. How can I hide the existing backup from Time Machine so that it will just give up and create a new backup? I don't recall this being a problem when using external hard drives. Now all the computers use the Time Capsule and I don't want to lose the old backup history.