Provided is a method and apparatus for providing a trust guarantee service in a digital broadcasting system, in which trust is guaranteed to a user in providing broadcasting streaming and file download services in a Digital Video Broadcasting (DVB) system. The method for providing a trust guarantee service through a terminal connected to a communication network in a portable broadcasting system includes the steps of determining an associated message generation request is received from the terminal, generating an associated message if the associated message generation request is received, and transmitting the generated associated message to a service provider.