Passwords are encrypted using bcrypt, an algorithm based on the Blowfish cipher.
Bcrypt is a password hashing function which incorporates a salt value to protect against rainbow table attacks. It has a significant advantage over a simply salted SHA-256 hash as it performs key strengthening on passwords. Key strengthening increases the resource cost to attackers when attempting to guess a password, rendering brute force attacks incredibly time and resource expensive. Simply put, once a password has been created, not even we can decrypt or read them.