## 2 Intelligent Sensors and Their Basic Security Issues
The presented research is focused on IT infrastructure for distribution of safety-critical and business-critical airplane software (EDS--Electronic Distribution of Loadable Software) and data [15]. In the automotive industry the assets can be loaded to different embedded electronic control units in vehicles [16], tachyographs, their motion sensors [17], _etc_. While continuing research on cyber-physical systems and eEnabled applications, some challenges were identified [16], like: building of specialized high-assurance PKI, use of formal methods for an end-to-end analysis of assets distribution systems, removing vulnerabilities and analyzing the impact of security on safety. The Common Criteria methodology can effectively support these efforts. The digital tachograph system [17-19] consists of a vehicle unit, the considered motion sensor and a smart card used to log in to this unit. The uniquely identified motion sensor includes a dedicated microcontroller placed, together with other circuits, on a relatively small sized printed circuit board--located in a sealed housing, which is screwed into the gear box. The movement detector (a hallotron) transforms the rotations to electric pulses which are sent to the microcontroller of the vehicle unit as a rough -Speed signal\" and to the motion sensor microcontroller. The data are processed concurrently in both locations and results are compared. The microcontroller exchanges information (distance travelled, speed, status, commands) with the vehicle unit through a cryptographically secured channel (-Data signal\"). The motion sensor performs advanced data processing in a heavy duty environment. The Common Criteria standard is used to evaluate the security of tachograph systems [20-22]. For the motion sensors, a full life-cycle model was applied, considering not only the operational environment, but also development-, manufacturing- and maintenance environments. This means, for example, that the threats existing in the development environment, e.g., -breaching design data\", -improper testing\" are considered because they may influence the motion sensor misbehaviour in its operational environment. Intelligent sensors can be used in control systems (field controllers) cooperating with SCADA as well. Security problems of these systems are growing because they are often parts of critical information infrastructures. The paper [23] discusses a new generation of SCADA systems used to control virtual utilities, aggregating distributed resources, like: microgrids, wind farms, fuel cells, _etc_. into single, centralized energy systems. Analyzing the security of these systems, the author of [23] concludes that SCADA products should be evaluated with the use of the Common Criteria standard to avoid compromising the security or safety of the critical infrastructure by these products. Moreover, the Common Criteria standard was applied in the development of the equipment used to secure wireless networks, like firewalls, routers, intrusion detection systems, and the microcontrollers to be used for intelligent sensors implementation, including control automation. Analyzing these works it is possible to create a common picture related to the intelligent sensors security features, applications and sensors co-operation within other systems. It should be also stressed that there is lack of knowledge and CC-related design patterns possible to use in the IT security development. The Common Criteria methodology requires a specific, methodical approach to the identification and description of security items, like threats, security policies, countermeasures, _etc_. The works discussing the character of known attacks [3-9] do not present them with the use of the CC methodology. Still, these works can be helpful to define these attacks according to the CC specification convention (_i.e.,_ attacker-asset-attack method/ used vulnerability) to define measures countering these threats and to provide the required rationale for the applied measures.