## 1 Introduction  
The paper discusses the application of the ISO/IEC 15408 Common Criteria (CC) assurance methodology [1] to the development of intelligent sensors. Assurance is understood as a situation when an entity, e.g., designed IT product or system, meets its security objectives, in other words, the implemented measures will be able to counter threats when they occur. The paper presents a specific security view of a group of numerous and diversified technical devices called intelligent sensors, which contains sensor-, processing- and communicating facilities. Generally, sensors are devices that measure some physical quantity and convert the result into a signal which can be read by an observer or instrument, but intelligent sensors are also able to process measured values. A number of such devices contain actuators as well. Intelligent sensors are used in many application domains, and the number of these domains is growing, though the number of finalized Common Criteria certification processes of these IT products is relatively low. The motivation of this paper is to provide developers with knowledge and specific design patterns related to the application of the Common Criteria methodology to the development of intelligent sensors. This can help them in a broader use of this methodology in dependable sensor solutions. Generally, security design patterns are reusable proven solutions to security problems with respect to the specific context, and they are usually related to the software development, e.g., as discussed in the book [2]. These solutions may concern different issues: how to design identification and authentication, access control based e.g., on passwords, how to implement an encrypted communication channel, communication path, packet filtering for a firewall, accountability subsystem, _etc_. With respect to the Common Criteria methodology these security design patterns are related to the security functions implemented within the IT product or system according to the security functional requirements. Another kind of security design patterns is discussed in this paper--patterns closely related to the Common Criteria methodology, expressing: assets, legal subjects, attackers, threats, security policies, assumptions and security objectives, used to elaborate the security requirements specification for the IT product or system, and finally, the security functions implemented in the IT product or system. Here discussed -Common Criteria (CC) related security design patterns\", mentioned briefly in the paper as -patterns\" or -design patterns\", are focused on the risk management issues, not on the IT security solutions. The CC-related patterns concern the design process (called here IT security development), can be used in many projects (_i.e.,_ they are reusable), but in a certain context (_i.e.,_ in the CC-methodology context). Such patterns can be applied for different kinds of IT products or systems but in the paper only the patterns subset related to sensors and sensor networks are discussed. The paper focuses on the identification of intelligent sensors common features, allowing us to define a generalized model of such devices and, on this basis, to elaborate CC-related design patterns which can be used to specify security models of intelligent sensors. The discussed patterns concern only two stages of the Common Criteria compliant IT security development but these stages are of key importance: the security problem definition and its solution. The paper includes the following sections. Section 2 contains a review of intelligent sensor security issues and sensor applications. Section 3 contains the CC methodology primer for sensor systems developers not familiar with this methodology. A generalized model of the intelligent sensor allowing to create the CC security model for itself is discussed in Section 4.