Authentication without pre-known credentials

A communication system includes a network device including a plurality of communication ports and a plurality of communication nodes coupled with the network device through the plurality of communication ports. The communication system further includes a controller that is configured to generate a security key and to send a new configuration along with a message authentication code to the network device, wherein the controller is further configured to break the security key into parts and send the parts of the security key to at least some of the plurality of communication nodes such that each of the at least some of the plurality of communication node receiving one part of the parts of the security key. The network device is configured to retrieve the parts of the security key from the at least some of the plurality of communication nodes, to assemble the security key from the retrieved parts of the security key and using the assembled security key to authenticate the new configuration.