Authentication in ad-hoc and sensor networks

In the near future microprocessors will be found almost everywhere from cellular phones to washing machines and cars. Once these are connected via a (wireless) communication channel to each other and possibly to already existing static computers this could form an extremely dynamic wireless network which may not have access to an infrastructure or centralized administration. Such a network is often referred to as ad-hoc network. It is particularly useful where a reliable fixed or mobile infrastructure is not available – e.g., after a natural disaster – or too expensive. If the network consists of very small computing devices that are able to sensor their environment, such a network is called a sensor network. As ad-hoc and sensor networks become more a part of everyday life, they could become a threat if security is not considered before deployment. For instance, ad-hoc networks might be used to increase vehicle traffic safety. However, if there are any security vulnerabilities, this technology might be open to attackers and thus endanger passengers. Authentication in ad-hoc networks is a core requirement for secure protocols and secure applications of ad-hoc networks. Thus authentication in ad-hoc networks is the focus of this work. The security issues for ad-hoc networks and sensor networks are different than those for fixed networks. This is due to system constraints in mobile devices, frequent topology changes in the network, and the weak physical security of low-power devices. Moreover in sensor networks, the sensors are exposed to physical attacks such as power analysis and probing. Consequently, protocols need to be designed that are robust against a set of malicious devices as well as compromised secrets. The main goals and achievements of this thesis are as follows: (1) to give an overview of authentication schemes and analyze how well they are suited to ad-hoc networks; (2) to analyze how well digital signature schemes can be used in ad-hoc networks and to compare signature schemes for this purpose;