where sensitive information forming part of a transactional flow application is required to be sent over an open network such as the internet , for example from a world wide web site , a time stamp and a location stamp are included in a request for such information from a user . the time stamp carries the time at which a previous page in the application was sent to the client and the location stamp carries the client address as provided for that previous page . preferably the stamps are encrypted and are thus protected at the user location .