Patent ID: 8792416

Claim:
A mobile communication system comprising a distribution server, a radio device, and a mobile station, wherein a key transmitter of the distribution server is configured to transmit a public key of the distribution server to the mobile station by use of a traffic channel for broadcast communication, wherein the traffic channel is a common traffic channel (CTCH) or a MBMS traffic channel (MTCH), a notification information transmitter of the radio device is configured to transmit notification information to the mobile station by use of either a paging indication channel (PICH) or a MBMS indication channel (MICH) for notifying a specific mobile station that there is incoming information, an electronic signature transmitter of the distribution server is configured to transmit and electronic signature to the notification information, to the mobile station, by use of the traffic channel for broadcast communication, and an authenticator of the mobile station is configured to authenticate the validity of the notification information based on the received electronic signature to the notification information and the public key of the distribution server.