Answer Description
Unfortunately, the only viable recovery option listed is to attempt to brute force the user's password. However, this method should only be used as a last resort.
Wikipedia
In cryptography, a brute-force attack consists of an attacker submitting many passwords or passphrases with the hope of eventually guessing correctly The attacker systematically checks all possible passwords and passphrases until the correct one is found Alternatively, the attacker can attempt to guess the key which is typically created from the password using a key derivation function This is known as an exhaustive key search A brute-force attack is a cryptanalytic attack that can, in theory, be used to attempt to decrypt any encrypted data (except for data encrypted in an information-theoretically secure manner) Such an attack might be used when it is not possible to take advantage of other weaknesses in an encryption system (if any exist) that would make the task easier
Brute-force attack - Wikipedia, the free encyclopedia