Update old stored md5 passwords in PHP to increase security

Question

At the moment I have a database with md5 passwords stored, a few years back this was considered a little more secure than it is now and it\'s got to the point where the pass

Answer 1

I looked into this subject a while back and found the following link of great use:

Secure hash and salt for PHP passwords

I also use the following to create a random salt:

public static function getRandomString($length = 20) {
    $characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    $string = '';
    for ($i = 0; $i < $length; $i++) {
        $string .= substr($characters, (mt_rand() % strlen($characters)), 1);
    }
    return $string;
}