Password Hashing
PHP Manual

Predefined Constants

The constants below are always available as part of the PHP core.

PASSWORD_BCRYPT (integer)
PASSWORD_BCRYPT is used to create new password hashes using the CRYPT_BLOWFISH algorithm.
PASSWORD_DEFAULT (integer)
The default algorithm to use for hashing if no algorithm is provided. This may change in newer PHP releases when newer, stronger hashing algorithms are supported.


Password Hashing
PHP Manual