I have an iPhone 5 fully encrypted local backup, with iCloud off, iCloud Keychain not never enabled etc.
I tried to use the encrypted backup and it is so well encrypted that it doesn't respond to my unlock password! (nor even to the 'plan B' could it possibly be this password? - nor to anything else ever used anywhere near an Apple device from my own mind-cloud) so it's not a backup! I should have used the post-it encrypted-backup password backup...
(I do actually have a 'nuclear-fence', armed guards, unfed dogs and various microwavey radary thingies that would have protected my post-it note collection from everyone except the NSA cleaning lady)