# Smart Devices Security Enhancement via Power Supply Monitoring +
## 3 Proposed Side-Channel Monitoring Device  
The main idea of the present paper was the monitoring of the supply current in order to detect abnormal operation of IoT devices. The concept is based on the fact that any operation of an electrical and electronic device is characterized by its consumption. Furthermore, considering that power consumption depends on the input characteristics, it may be concluded that a system performing an explicitly defined operation is bounded in a characteristic power consumption range. Considering that IoT devices are limited in terms of functionality and operational features, it is expected that any deviations from normal operation will result in analogous deviations regarding the consumed power.  
Thus, any malicious action against the IoT device is expected to be detected via the power consumption deviation caused by the malicious attack source.  
The contribution of this paper is the introduction of an external mechanism to the IoT devices, which has a generic use and is easily adaptable to any IoT device. This mechanism is a power supply monitoring system specifically designed for the targeted device which analyzes the device's electrical behaviour without affecting its operation. This can provide a good indication regarding the possibility that the device operates in an abnormal way. It is expected that deviations in the network or processing activity of the IoT device will trigger analogous deviations regarding energy consumption. Since the electrical behaviour of the IoT device is stored to the external monitoring system, any effect of a malicious attack to the IoT device may not be masked by the attacker. Violation of normal operation thresholds are triggering the detection of the attack. Throughout this work, the pre-characterization of the normal operation thresholds of the supply current is performed by the user. In the last section of this work, the future work reveals the next steps towards an automatic set of the normal operation supply current range.  
In this paper, we set up a device as an intermediate observer between the device that we want to monitor and its power supply. This approach is realistic since all devices offer access to their power supply. The proposed system can be eventually used to detect reliability problems and security-related attacks against the device. The constructed setup as well as the relative measurement data are presented throughout the rest of the paper.  
The topology of a final solution is presented in Figure 1, where any home connected to the Internet may use the services of an IDS provider. To date, a botnet of smart devices attacks either the IDS or the targeted device. The second scenario is in the scope of this paper. Each smart device is connected to the energy grid (power supply) via the proposed monitoring devices and to the Internet via the router. Any deviation from the expected operation is reported to the IDS and at the same time, fail safe procedures may be triggered, based on security policies. In this work, research was focused only on anomaly detection.  
Figure 1: Topology of the monitoring devices in a household.