In the last several years IEEE 802.15.4 [1]

No abstract

Wireless sensor networks (WSNs) do not have a fixed infrastructure and consist of sensor nodes that perform sensing and communicating tasks. The WSNs have large application spectrum such as habitat monitoring, military surveillance, and target tracking, where sensor nodes may operate distributed in highly dynamic environments. Battery-constrained sensor nodes may aggregate the sensed data, localize themselves, and route the packets in an energy-efficient and decentralized manner to enable running the applications. Agents are capable of independent and autonomous action, so that they can successfully carry out tasks that have been delegated to them, thus agent-based approaches are very suitable to apply as the solution of the problems occurring in WSNs. So far many agent-based approaches were proposed for WSNs. This paper surveys the agent technologies for sensor networks by providing a classification, objectives and costs of these approaches with the open research problems. To the best of our knowledge, this is the first study that covers the intersection of the agent technology and sensor networks from a wide perspective.

Considering the computer authentication, any password shall not only be private to its owner but also be chosen as not to be predicted easily by others. The passwords used in authentication processes of any critical system should be strong as not to be cracked easily. In this context, the strong password choice gets significance for the general system security. This study aims to reveal the proper and improper properties on password preferences via examining the real samples. The method used in this work is first to gather the real passwords in plaintext, then to crack the encrypted forms of them and finally to investigate statistical queries on those passwords in order to distinguish the common weak and strong characteristics. As the case study, the experiments are conducted on real passwords of Turkish users in an actively running system. The results of the experiments are categorized for weak and strong passwords. Moreover, the common tendencies on password choice are evaluated.

Wireless Sensor Network (WSN) is a promising technology that has attracted the interest of research in the last decade. Security is one of the fundamental issues in sensor networks since sensor nodes are very resource constrained. An attacker may modify, insert, and delete new hardware and software components to the system where a single node, a specific part of the sensing area, and the whole network may become inoperable. Thus, the design of early attack detection and defense mechanisms must be carefully considered. In this chapter, the authors survey attacks and their defense mechanisms in WSNs. Attacks are categorized according to the related protocol layer. They also investigate the open research issues and emerging technologies on security in WSNs.