Apple - Possible to find iPhone encrypted backup password in Keychain files?

When you encrypt iPhone backup on Mac, a password entry dialog will pop up to ask you to enter your password and display a "Remember this password in my Keychain" check box. If you checked the checkbox, your iPhone encrypted backup password was saved in your Keychain files. So you can open the Keychain to show the encryption password once you forget it.

If you did not check that "Remember this password in my Keychain" option, your iPhone backup password would not be saved in your Keychain. So it is impossible to find the encryption password in the Keychain or anywhere on your Mac. In this case, you have to use a third-party application to recover iPhone encrypted backup password on your MacBook.

This post would be helpful: http://www.isumsoft.com/it/find-iphone-encrypted-backup-password-in-keychain-on-macbook/

iOS Backup entry in Keychain Access

In your Keychain Access app, look for an entry of type Passwords named iOS Backup:

If you instructed iTunes to save your password in the keychain when you backed up, it should be listed there.

If you saved the encryption password to the keychain, then yes you can retrieve it from Keychain Access. I did exactly that last week. I believe you can filter your keychain by looking for "iPhone backup".