How to encrypt url before go.php?

Question

PHP

Made a go.php page to redirect external links. I would like to know how they do url encryption before go? You need to hide your domain so that the external link looks like:

<a href="/go?xxxxxxxx"> И <img src="/kartinka/vesna.png">

The redirect code is:

$links = parse_ini_file('links.ini');

if(isset($_GET['go']) && array_key_exists($_GET['go'], $links)){
  header('Location: ' . $links[$_GET['go']]);
exit;
}
else{
  header('HTTP/1.0 404 Not Found');
  echo 'Unknown link.';
}

Added to htaccess file:

RewriteEngine On
RewriteCond $1 !^(index\.php)
RewriteRule ^(.*)$ index.php?go=$1 [L]

Answer 1

base64_encode() /*_decode()

Answer 2

Sample code can be seen in another question thread. Search in answers: Some of the old code that no longer works in php7 .