since there's a + sign at the end of the base64 encoded string, it might cause problems in a browser, as a + sign can also be used to replace spaces. For instance, placing this url
http://mysite.com/mypage?var=Hello World might end up like this
http://mysite.com/mypage?var=Hello+World So whenever you grab the value of the $_GET['var'] variable, php might convert the plus sign to a space character.
To prevent this, use the functions
urlencode and
urldecode