According to an embodiment of the invention, a method for processing a plurality of service requests in a client-server system includes server steps of receiving at least one request for service from a client and providing a level of service based on a trust level provided in the at least one request. According to another embodiment, a method of authenticating messages includes steps of: embedding authentication information into a message at the application level; downloading a script from a computer for sending the message; running said script to send said message to a server; and checking said message by said server at the network level.