A security controller, SC, restoration method, comprising: designating, by a master node, a node to which a backup SC belongs, wherein the master node comprises an original domain master, DM, node; sending, by the master node to a first node, a message indicating the backup SC, wherein the message indicating the backup SC comprises an identifier of the node to which the backup SC belongs; and in a case in which a node to which an original SC belongs is disconnected, sending, by the master node to the first node, a message for enabling an SC function to the first node for performing authentication, according to the message for enabling an SC function, on the node to which the backup SC belongs, wherein the message for enabling an SC function comprises the identifier of the node to which the backup SC belongs; wherein when the master node is the same as the node to which the backup SC belongs, the first node is a node except the master node; and the method further comprises: activating, by the master node, an SC function of the master node, and performing authentication within the master node; or wherein when the master node is different from the node to which the backup SC belongs, the first node is a node except the master node and the node to which the backup SC belongs; and the method further comprises: sending, by the master node to the node to which the backup SC belongs, the message for enabling an SC function and/or a re-authentication request message for activating an SC function of the node to which the backup SC belongs, and performing authentication within the node to which the backup SC belongs. designating, by a master node, a node to which a backup SC belongs, wherein the master node comprises an original domain master, DM, node; sending, by the master node to a first node, a message indicating the backup SC, wherein the message indicating the backup SC comprises an identifier of the node to which the backup SC belongs; and in a case in which a node to which an original SC belongs is disconnected, sending, by the master node to the first node, a message for enabling an SC function to the first node for performing authentication, according to the message for enabling an SC function, on the node to which the backup SC belongs, wherein the message for enabling an SC function comprises the identifier of the node to which the backup SC belongs; wherein when the master node is the same as the node to which the backup SC belongs, the first node is a node except the master node; and the method further comprises: activating, by the master node, an SC function of the master node, and performing authentication within the master node; or wherein when the master node is different from the node to which the backup SC belongs, the first node is a node except the master node and the node to which the backup SC belongs; and the method further comprises: sending, by the master node to the node to which the backup SC belongs, the message for enabling an SC function and/or a re-authentication request message for activating an SC function of the node to which the backup SC belongs, and performing authentication within the node to which the backup SC belongs.