The present invention particularly relates to a digital content providing service method and a content execution device for the same, for maximizing user convenience and maintaining a sufficient level of security using a smart card. The inventive content execution device includes an independent authentication unit for storing a tool necessary for executing content; an authentication support module for providing a data communication channel between the smart card and an external broadcasting server; a tool agent for calling the tool stored in the independent authentication unit; and a content execution unit for executing content data received from the external broadcasting server. The content execution device included in a content authority management system of the present invention employs the smart card for user authentication and/or content playing tool management. Accordingly, a user can freely executing his/her licensed content in different content execution devices by conveniently removing and reinserting the smart card, without separate measures. Moreover, according to the present invention, a user can effectively use content from different broadcasters.