Study and Verification of Covert Channels for Process Layer Network in Smart Substations

The covert channel is a dangerous cyber-attack threat to industry control networks; however, it is a lack of specific research for the network environment of smart substations. Existing studies merely explore the theoretical existence of covert channels in substation networks without building and verifying. In this paper, the process layer network environment of substations has been analyzed and potential information hiding schemes are proposed for covert channels. Furthermore, a laboratory simulation environment is developed to verify the efficacy of transmitting covert information. Results demonstrate that these covert channels can successfully transmit data while remaining undetectable by existing network detection equipment.