Php encrypt decrypt url

When developing web applications sometimes we encounter situations where we need to encrypt/decrypt url or some code or some information. For such situations I wrote a simple php script using the default php functions:
base64_encode()
base64_decode()
Now the use of these functions is quite simple. For example if you want to pass some critical information like password in the url like:


Example:
Encode:- http://www.abc.com/abc.php?param0=<?php echo base64_encode('blog'); ?>

Example:


<?php
$param0 = $_REQUEST['param0

'];

echo base64_decode(

$param0

);
?>