A method and systems for protecting the identification of a subscriber when a service provider transmits a subscriber request to a content provider in a distributed network environment, such as Internet. After the user sends a request to a service provider to which he has subscribed, the service provider encrypts the user identifier before transmitting this request with the encrypted user identifier to the content provider. Upon reception, the content provider uses an authentication Web Service supplied by the service provider for certifying the user identifier. If the user identifier is certified, the content provider transmits the requested content to the service provider, which formats it before sending it to the user. The content provider may charge the user through the service provider.