A method for receiving encryption information by a broadcast service distribution/adaptation, BSD/A , for service protection in a mobile broadcast system, the method characterized by comprising: transmitting, by a service protection, SP, key distribution, SP-KD , in the BSD/A , a registration key material, RKM, request message for requesting delivery of an RKM for registration of a broadcast service of a terminal, to a broadcast subscription management, BSM ; receiving, by the SP-KD in the BSD/A , an RKM request response message from the BSM ; transmitting , by the SP-KD in the BSD/A , to the BSM , a long-term key message, LTKM, request message for requesting delivery of an LTKM; receiving , by the SP-KD in the BSD/A , an LTKM request response message from the BSM ; transmitting , by the SP-KD in the BSD/A , to the BSM , a short-term key message, STKM, request message for acquisition of an STKM including a traffic encryption key, TEK, used for decryption of the broadcast service by the terminal; and receiving , by the SP-KD in the BSD/A , an STKM request response message from the BSM , wherein the RKM request message includes a service identifier, ID, and the RKM request response message includes the service ID and the RKM, wherein the LTKM request message includes the service ID, and the LTKM request response message includes the service ID and the LTKM, wherein the STKM request message includes the service ID, and the STKM request response message includes the service ID and the STKM, wherein the STKM is decrypted by the terminal using a service encryption key, SEK, obtained as a result of decryption of the LTKM, and wherein the RKM, the LTKM and the STKM are transmitted to the terminal by the SP-KD in the BSD/A . transmitting, by a service protection, SP, key distribution, SP-KD , in the BSD/A , a registration key material, RKM, request message for requesting delivery of an RKM for registration of a broadcast service of a terminal, to a broadcast subscription management, BSM ; receiving, by the SP-KD in the BSD/A , an RKM request response message from the BSM ; transmitting , by the SP-KD in the BSD/A , to the BSM , a long-term key message, LTKM, request message for requesting delivery of an LTKM; receiving , by the SP-KD in the BSD/A , an LTKM request response message from the BSM ; transmitting , by the SP-KD in the BSD/A , to the BSM , a short-term key message, STKM, request message for acquisition of an STKM including a traffic encryption key, TEK, used for decryption of the broadcast service by the terminal; and receiving , by the SP-KD in the BSD/A , an STKM request response message from the BSM , wherein the RKM request message includes a service identifier, ID, and the RKM request response message includes the service ID and the RKM, wherein the LTKM request message includes the service ID, and the LTKM request response message includes the service ID and the LTKM, wherein the STKM request message includes the service ID, and the STKM request response message includes the service ID and the STKM, wherein the STKM is decrypted by the terminal using a service encryption key, SEK, obtained as a result of decryption of the LTKM, and wherein the RKM, the LTKM and the STKM are transmitted to the terminal by the SP-KD in the BSD/A . <EOS>