Iphone itunes encryption password

If the backup you're trying to restore from is encrypted, you will not be able to use that backup if you can't remember the encrypted backup passcode.

If on a Mac, & you elected to save the passcode to your Keychain, you can recover the passcode from your Keychain. Otherwise, your data is unrecoverable.

While you can continue to sync/backup, if you can't remember it & want to remove it, you'll have to delete your existing backups & restore the phone as a new device. Your data will be unrecoverable.

My code was the same that I use to unblock the phone. The first time I backed up, there was no problem, the second time yes.

Key chain is just another link in getting things screwed up.