The SecurityGroupIdwith DataType Stringis the identifier for a SecurityGroupin the Security Key Server. It is unique within a SKS.

The parameter is null if the SecurityModeis NONE_1.

If the SecurityModeis not NONE_1 the SecurityGroupIdidentifies the SecurityGroup. The SecurityGroup defines the SecurityPolicy and the security keys used for the NetworkMessagesecurity. The PubSubGroupdefines the SecurityModefor the NetworkMessagessent by the group.