I'm trying to set up password salting on our website, and found the PBKDF2 functions at https://defuse.ca/php-pbkdf2.htm
When I try it, I get:
Fatal error: mcrypt_create_iv(): Could not gather sufficient random data in include\PBKDF2.php on line 23
I'm not sure if I need to do anything to make this work. It's running on IIS7.5