Method for using contents, method for sharing contents and device based on security level

PURPOSE: A method for using contents, a method for sharing contents and a device based on security level are provided to prevent a device which does not satisfy usage requirement conditions of contents from using contents, thereby improving security. CONSTITUTION: An IPTV receiving module(41) transceives data with a service provider(20). A security controller performs security control related functions. The security controller receives contents transmitted from the service provider and content related information. The security controller controls whether to transmit the contents.