A distributed control system comprising: an electronic control unit; and one or more distributed control modules, wherein the electronic control unit is configured to establish secure communication with a distributed control module of the one or more distributed control modules by: upon determination that a previously negotiated session key is stored on the electronic control unit: transmitting encrypted communications between the electronic control unit and the distributed control module using the previously negotiated session key; negotiating a new session key with the distributed control module; and storing the new session key; and upon determination that the previously negotiated session key is not stored on the electronic control unit: transmitting unencrypted communications between the electronic control unit and the distributed control module; negotiating the new session key with the distributed control module; and after negotiating the new session key with the distributed control module: ceasing transmission of unencrypted communications between the electronic control unit and the distributed control module; transmitting encrypted communications between the electronic control unit and the distributed control module using the new session key; and storing the new session key. an electronic control unit; and one or more distributed control modules, wherein the electronic control unit is configured to establish secure communication with a distributed control module of the one or more distributed control modules by: upon determination that a previously negotiated session key is stored on the electronic control unit: transmitting encrypted communications between the electronic control unit and the distributed control module using the previously negotiated session key; negotiating a new session key with the distributed control module; and storing the new session key; and upon determination that the previously negotiated session key is not stored on the electronic control unit: transmitting unencrypted communications between the electronic control unit and the distributed control module; negotiating the new session key with the distributed control module; and after negotiating the new session key with the distributed control module: ceasing transmission of unencrypted communications between the electronic control unit and the distributed control module; transmitting encrypted communications between the electronic control unit and the distributed control module using the new session key; and storing the new session key. upon determination that a previously negotiated session key is stored on the electronic control unit: transmitting encrypted communications between the electronic control unit and the distributed control module using the previously negotiated session key; negotiating a new session key with the distributed control module; and storing the new session key; and transmitting encrypted communications between the electronic control unit and the distributed control module using the previously negotiated session key; negotiating a new session key with the distributed control module; and storing the new session key; and upon determination that the previously negotiated session key is not stored on the electronic control unit: transmitting unencrypted communications between the electronic control unit and the distributed control module; negotiating the new session key with the distributed control module; and after negotiating the new session key with the distributed control module: ceasing transmission of unencrypted communications between the electronic control unit and the distributed control module; transmitting encrypted communications between the electronic control unit and the distributed control module using the new session key; and storing the new session key. transmitting unencrypted communications between the electronic control unit and the distributed control module; negotiating the new session key with the distributed control module; and after negotiating the new session key with the distributed control module: ceasing transmission of unencrypted communications between the electronic control unit and the distributed control module; transmitting encrypted communications between the electronic control unit and the distributed control module using the new session key; and ceasing transmission of unencrypted communications between the electronic control unit and the distributed control module; transmitting encrypted communications between the electronic control unit and the distributed control module using the new session key; and storing the new session key.