src/Core/LTIX.php
public static function getCompositeKey($post, $session_secret) {
        $comp = $session_secret .'::'. $post['key'] .'::'. $post['context_id'] .'::'.
            U::get($post,'link_id')  .'::'. $post['user_id'] .'::'. intval(time() / 1800) .
            $_SERVER['HTTP_USER_AGENT'] . '::' . __FILE__;
        return md5($comp);
    }
public static function getCompositeKey($post, $session_secret) {
        $comp = $session_secret .'::'. $post['key'] .'::'. $post['context_id'] .'::'.
            U::get($post,'link_id')  .'::'. $post['user_id'] .'::'. intval(time() / 1800) .
            $_SERVER['HTTP_USER_AGENT'] . '::' . __FILE__;
        return md5($comp);
    }
public static function getCompositeKey ( $ post , $ session_secret ) { $ comp = $ session_secret . '::' . $ post [ 'key' ] . '::' . $ post [ 'context_id' ] . '::' . U :: get ( $ post , 'link_id' ) . '::' . $ post [ 'user_id' ] . '::' . intval ( time ( ) / 1800 ) . $ _SERVER [ 'HTTP_USER_AGENT' ] . '::' . __FILE__ ; return md5 ( $ comp ) ; }
session secret.  Also make these change every 30 minutes
session secret . Also make these change every 30 minutes