Abstract: Techniques for securing communication between a plurality of network computing devices over an unsecured network can include providing a plurality of communication security devices in secure communication with the network computing devices. A list of authorized communication devices can be established that specifies one or more computing devices with which each of the plurality of network computing devices are authorized to communicate. A communication packet from a source network computing device will specify a destination network computing device. A communication security device that receives the packet will transmit the packet to another communication security device associated with the intended destination network computing device when the network computing devices are authorized to communicate. The other communication security device will transmit the packet to the intended destination network when the network computing devices are authorized to communicate.