User password hashing with PBKDF-SHA1

Use of a powerful encryption system to store the user's password
securely in the database. The encryption system consists in a salted
password hashing with PBKDF-SHA1 key derivation process. The password is
stored in a string with length 70 and with the following structure:
PBKDF2_iterations: salt: hashf . Delimited by  " : ".