# Smart Devices Security Enhancement via Power Supply Monitoring +
## 2 Related Work  
A significant number of research efforts, presented through the last years, have been related to IoT devices and issues related to their operation. A number of works that reflect the research have been conducted recently, regarding IoT devices and issues regarding security and availability. The most important issues that were depicted from the conducted study were the reliability (directly associated with availability) and the security of IoT devices. The reliability of IoT devices is significant and can be affected by various factors such as the operational environment, the manufacturing process (genuine or counterfeit, trojan hardware) [8] and the faulty condition of the device itself (malfunctioning, transient errors, etc.) [9]. In general, works associating availability with the operation of IoT highlight hardware as a key point. Although, this issue of reliability is critical for numerous applications, researchers usually study it only theoretically or under laboratory conditions. Reliability, however, is extremely prone to operational conditions [10] and needs to be further investigated. What is very interesting as a case study is the study of similar (or identical) smart devices operating under various conditions (normal to extreme) and the calculation of the degradation of reliability (as a metric) based on the Mean Time Before Failure (MTBF) for each environment. However, apart from this case study, which is typical for expected conditions of operation, there are cases when hardware is not operating as expected. Such cases include the effect of a Trojan hardware, or a side channel attack. Taking lessons from other disciplines like circuit testing, at the beginning of the anomalous operation, this resembles the effect of the Single Event Upset (SEU) [11]. Thus, many hardware anomalous operations may be characterized as deviations of the characteristic operation. Concerns software of an IoT device, the detection of an execution of a malicious code or the effect of an attack is different. Although, in the past, computing machines were based on similar architectures and their implementations resulted in bulky systems, using complex design methodologies, the process to protect them and generally ensure security was feasible. Nowadays, the diversity of IoT devices along with their shrinking processing capabilities have made their protection a very hard task. Regarding security issues, the recent growth in usage of heterogeneous computing devices [12] has made the protection of a computing infrastructure against all kind of risks, such as cyber-attacks, malfunctioning or privacy leaks, much more difficult [13; 14]. A lot of recently reported cyber-security problems are directly or indirectly related to the unprecedented switch in the form of today's devices. As a consequence, IoT devices have been recently used to construct massive botnets and execute distributed denial of service attacks, the size of which is larger than that of any known attack in the past [15; 16]. In practice, the insufficient security measures that the vendors usually implement on such devices actually extend the attack surface, offering new opportunities in terms of building more efficient botnets. Additionally, the acquisition and the nature of data processed by these devices constitutes an important privacy threat for users [17; 18]. IoT devices, installed at work or even in public places, monitor and store data relevant to the activities happening in their observation space. In practice, an IoT device collects data relevant to the activity of the people present in these spaces, sometimes even without their consent or even knowledge. The monitoring, storing, processing or even use for profit of such data, has serious privacy implications for the people involved. The market for producing IoT devices is growing exponentially. Multiple new vendors claim a share of this market, introducing new IoT devices of various configurations and features. This has direct implications on the quality of new IoT devices.