Upon detection of a new traffic flow, a registration node can dynamically register the new traffic flow with a key server policy manager by sending a registration request on behalf of the new traffic flow. A registration request indicates the new traffic flow should be protected by a security group. A registration request may also include a request to dynamically generate a new security group to protect the traffic flow. The registration request is received by a key server policy manager, which performs authentication and authorization checks of the requesting registration node, and determines whether to accept or reject the registration request. If accepted, the key server policy manager registers the new traffic flow by including a description of the traffic flow in a group policy of an existing security group or a newly created security group, depending on the registration request.