Abstract: A Right Object renewal method and apparatus for a right-protected digital broadcast service that is capable of predicting the expiration of a Right Object issued for the right-protected broadcast channel and renewing the Right Object prior to the expiration of the Right object based on the predicted expiry is provided.

Abstract: A Right Object renewal method and apparatus for a right-protected digital broadcast service that is capable of predicting the expiration of a Right Object issued for the right-protected broadcast channel and renewing the Right Object prior to the expiration of the Right object based on the predicted expiry is provided.

Abstract: A Right Object renewal method and apparatus for a right-protected digital broadcast service that is capable of predicting the expiration of a Right Object issued for the right-protected broadcast channel and renewing the Right Object prior to the expiration of the Right object based on the predicted expiry is provided.

Abstract: A user interest information-collecting method and apparatus of the present invention are provided for collecting user interest information on the basis of program viewing-behavior patterns of a user. The user interest information-collecting method includes extracting program guide information from a digital broadcast data received by the digital broadcast receiver; classifying by keyword information items contained in the program guide information; selecting at least one of the information items as user interest fields on the basis of user-viewing history; retrieving relevant information items of the user interest fields; and designating at least one of retrieved relevant information items selected by the user as user interest information item.