Fatal error: Uncaught Error: Call to undefined function mcrypt_get_iv_size() in /opt/www/internett/php/PHP_Book/eksempler/ch21 - Secure PHP Programming/mcrypt_encrypt.php:2 Stack trace: #0 {main} thrown in /opt/www/internett/php/PHP_Book/eksempler/ch21 - Secure PHP Programming/mcrypt_encrypt.php on line 2