URL Encoder: Encode data to pass securely between two pages

This class is used to encode data being passed between two sources that can be either two pages via URL arguments or by any other data storage media like databases, files or sessions variables.

It works by taking an array of variables and their values and encode it using a private key only known by the server scripts to create a string that represents those variables.

When another page script receives the encoded data, the class can decode it and restore the variables original values using the same server private key.

This way the class can be used pass or store data without the possibility of tampering by the users of a site or any other agent that does not have access to the site scripts.