If you are sending sensitive instructions from on page to another, Data Transmission Shield is often important to hide and protect what you are sending to prevent cross site scripting and other malicious attempts to hack your sites and applications.

The shield class protects your data by using mcrypt to encrypt the information into a hashed value. This is then sent as one value unreadable value. For example a standard GET form would send data like so:
http://www.myserver.com/add.php?user=buggedcom&page;=register

The shield class combines all this data into one value so people can no longer observe what data is being sent. It would turn the above example into:
http://www.myserver.com/add.php?shield=sN5V3BBa1FHSTdV3tea1FHBSTaf4nj43....

Each encrypted value contains a digital id. One that you set and the directory path that the script resides in. If neither match the data is not decrypted and is returned as false.

Now Data Transmission Shield also features javascript DES encryption methods that have been linked from another opensource work. This usage enables people to provide form submission encryption to data in non https forms.