Multicast key negotiation method suitable for group calling system and a system thereof

摘要

The present invention discloses a multicast key negotiation method suitable for group calling system and a system thereof. The method includes that: a user terminal (UT) negotiates about a unicast key with a base station (BS), derives an information encryption key and an integrity verifying key according to the unicast key, and registers a service group identifier that the UT belongs to at the BS; the BS notifies the UT the multicast key of the service group that the UT needs to apply, constructs a multicast key notification packet, and sends it to the UT; after receiving the multicast key notification packet sent by the BS, the UT obtains the multicast key of the service group that the UT needs to apply by decrypting a service group key application list, constructs a multicast key confirmation packet, and sends it to the BS; the BS confirms that the multicast key of the UT service group is built successfully according to the multicast key confirmation packet sent by the UT.

主权项

1. A multicast key negotiation method suitable for a group call system, comprising:
a) negotiating a unicast key between a UT and a BS, deriving an information encryption key and an integrity check key from the unicast key, and registering by the UT to the BS identifiers of service groups to which the UT pertains; b) notifying, by the BS, the UT of multicast keys of service groups to be applied by the UT, constructing a multicast key notification message which comprises a service group key application list and a message integrity check value, and sending the multicast key notification message to the UT, wherein the service group key application list, which is a ciphertext obtained by encryption using the information encryption key, comprises identifiers and the multicast keys of the service groups to be applied by the UT; c) decrypting, by the UT, the service group key application list on receiving the multicast key notification message sent by the BS to obtain the multicast keys of the service groups to be applied by the UT, constructing a multicast key confirmation message which comprises a service group key response list and the message integrity check value, and sending the multicast key confirmation message to the BS, wherein the service group key response list, which is a ciphertext obtained by encryption using the information encryption key, comprises the identifiers of the service groups which have been applied; and d) confirming, by the BS, that the multicast keys of the service groups for the UT have been established successfully upon the multicast key confirmation message sent by the UT.