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.

If the SecurityModeis not NONEthe 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.