This might be a long shot, but I have a problem where I've lost the encryption password to an iPhone backup created with iTunes for Windows. On a mac this shouldn't bee too much of a problem, since the password is persisted in the keychain, at least as long as you still have access to machine the backup was created on.
The problem is that iTunes asked to set the encryption password when that options was checked several months ago, and never again. I created a backup moments before resetting the device, which worked just fine, but was unable to restore from the backup because of the lost password. I was sure that this would be the iCloud account password and only saw the error when it was too late.
I had a look around the iTunes files on the Windows machine where the backup was created and found a file named keychain-2.db, which seems to be an sqlite db with some probably encrypted data (or binary blobs?). The tables inside are named cert, genp, inet, keys, sqlite_sequence, tversion.
Is there any possible hope of restoring the backup encryption password through this? I don't have a lot of hope, since I haven't found anything regarding this idea online so far. Should any more information be necessary or just interesting, I'd of course love to provide it.
Best Answer
Various ideas:
Have you tried any typo variations on your iCloud password (since you mentioned you thought it was the same)? Another goofy thing about the backup encryption is that there's no second password field to ensure it's typed correctly.
If I remember right, Elcomsoft Phone Breaker's free trial will let you preview two characters from the backup password on Windows in case that will help trigger your memory. I'm not sure if it's compatible with iOS 10.2 and later backup encryption yet though. (I don't work on this program, but I work on other software that reads iPhone backups, and sometimes I suggest this to help people remember their password ;))
Did you setup that iPhone by restoring from a previous encrypted backup? If so, the backup password should be the same password for the backup you set up from.
Otherwise, you're pretty much left to trying to put yourself in the mindset of a few months ago to remember what you would have used for a password. :(