# Evaluation of Resource Exhaustion Attacks against Wireless Mobile Devices
## 1 Introduction  
Currently cyber-physical systems including mobile embedded microcircuits, physical actuators, detectors as well as traditional networking and executive units are becoming more common in our life. Management in cyber-physical systems comprises both software/informational and physical aspects of interaction between devices and users. Such interaction along with the critical nature of such systems and remote access via the Internet determine the importance of solving cyber-physical security problems connected to protection of the devices, customer data and the organizational/technical infrastructure. Besides targeted malicious actions exploiting the specificity of a concrete system and its devices, more universal influences, violating the availability of the system's devices, are gaining peculiar importance. The mobile nature of the devices and the possibility of their functioning in an autonomous mode as well as the constraints on available battery resources have led the devices to be vulnerable to energy resources exhaustion (ERE) attacks. In relation to the wide range of cyber-physical applications--transport systems, power grids, water supply control systems, systems of implantable medical devices, etc.--the consequences of their availability violation can lead to serious man-made disasters and significant financial damages caused by inability of the devices partly or fully to perform their business functions. The core features of ERE attacks are seen as complexity of their recognition, the relative effectiveness of such attacks, and their volatility. The complexity of an ERE attack detection is determined, first, by the fact that often the effect on the device is implicit--by sending through the Internet or a localcommunication port a sequences of false demands to the device, which are not naturally isolatable as attacking actions. Second, to keep track of ERE attacks it is necessary not only to analyze the discharging of the battery, but also the discharging speed change. Third, the detection of ERE attacks may be determined by independent aspects of energy resource discharge due to legal software and clients. By affecting a device, an ERE attacker can select the more productive techniques of carrying out the fast draining of the energy resource allotted for the device operation within days, months or even several years. These circumstances together with a tendency to insufficient security of modern cyber-physical systems from ERE attacks and a lack of effective means for monitoring such attacks lead to the need for additional research in this field and solving the problem of strengthening the security of devices from ERE attacks. It should be noted the architecture of a target device may not assume the presence of technical possibilities for detailed accurate measurement of its energy consumption. Besides, the form factor and operating conditions of the end product can prevent the connection of external hardware and software units to read data on power consumption. In modern scientific and technical literature, the issues of ERE attacks are mainly represented by current studies of:  
* specific types of ERE attacks, such as vampire attacks [1; 2; 3], denial-of-sleep attacks [4; 5; 6; 7; 8], attacks on specific crypto-protocols, causing increased power consumption on their executing devices [9], various jamming attacks [10; 11], replay attacks and collision attacks [12], etc. ;
* specific applications and systems analyzed for possible ERE attacks, such as attacks on personal portable mobile devices in direct line of sight [13; 14], combined attacks on mobile devices, using vulnerabilities of a cellular network server [15], attacks on separately located sensors [16], attacks on mesh networks built on specific network protocols [17], attacks on drones [18], attacks on implantable medical devices, taking into account various ways to replenish their charge [19], etc.