In an embodiment, a server determines to update at least one group session key (GSK) parameter for a given multicast group, the at least one GSK parameter configured to permit encryption, decryption and/or authentication of multicast messaging exchanged between members of the given multicast group during a multicast communication session. The server sends a notification to a plurality of multicast group members of the given multicast group that an update of the at least one GSK parameter for the given multicast group is available. At least one of the multicast group members receives the notification and sends a provisioning request to retrieve the updated at least one GSK parameter, the provisioning request including information specific to the given multicast group member. The server generates and encrypts the updated at least one GSK parameter and sends the encrypted at least one GSK parameter to the at least one multicast group member.