A Mimic Cloud Ruling Method for Defending Against Time-Delayed Covert Channel Attacks

The mimic cloud system can effectively defend against security threats such as vulnerabilities and backdoors in the cloud environment, and has been widely used in important fields such as finance, military affairs and cyber space. However, its unique adjudication mechanism provides a potential way to implement time-delayed covert channel attacks. In response to this potential security threat, a mimic cloud ruling method to defend against time-delayed covert channel attacks is proposed. First of all, from the perspective of information theory, the attacker uses the response delay sample mean and variance as the feature statistics to deduce the detection rate formula. Furthermore, in order to defend against time-delayed covert channel attacks, basic countermeasures and first-come-first-rule strategies are proposed to reduce attackers' use of response time-delay difference characteristics to transmit information. Finally, a prototype system based on Nginx was developed and extensively tested to verify the harm of the time-delayed covert channel attack and the effectiveness and feasibility of the proposed defense strategy.