gistfile1.php

<?php

class securehasing {
    public static function registerImplementation($alias, $class) {}
    public static function instanceForImplementation($alias = 'sha512') {}
}


interface securehasing_interface {
    public function random($length = 12);
    public function phonemic($length = 8, $flags = null);
    public function compare($password);
}

class sha512securehasing implements securehasing_interface {
    protected function randomBytes($length) {}
    
    public function random($length = 12) {}
    public function phonemic($length = 8, $flags = null) {}
    public function compare($password) {}
}

// default include whatever
securehasing::registerImplementation('sha512', 'sha512securehasing');

// user tobias existiert und hat eine implementierung in der datenbank hinterlegt
$hash = securehasing::instanceForImplementation($user->hashingImplementation);
$hash->compare('baz');

// user christian ist neu, nutzt also den default
$hash = securehasing::instanceForImplementation()
$hash->phonemic();