a data transfer method performed at a proxy server includes intercepting a data request from a client computer that is directed to a target server , encrypting profile information , augmenting the data request by adding the encrypted profile information to the data request , and sending the augmented data request to the target server . a data transfer method that is performed at an information server includes receiving a data request from a proxy server , extracting profile information added to the data request by the proxy server , using the extracted profile information to generate a response , and sending the response to the proxy server .