TABLE OF CONTENTS If mobile ad hoc networks (MANETs) [1] are to go beyond their current, limited, use in military systems or where there is complete ownership by one party, then there will need to be security mechanisms in place. This chapter focuses on the security-related issues inherent in such networks, and in particular upon participation incentive schemes. A more general description of ad hoc network technologies can be found in Chapters 6 and 7.
Mobile ad hoc networks are formed from communications devices without any centralised control. Each device can act as a router to transmit its neighbours packets as well as transmitting and receiving its own packets. Distant devices are reached by forming a chain of devices. This is illustrated in Figure 9.1 where device A wants to communicate with device E, but its transmission range only reaches device B.
Ad hoc networks have been used for many years by the military where they offer a high degree of resilience, and can be deployed rapidly and with no fixed infrastructure.
In a general, publicly owned ad hoc network, security issues arise because:
devices are owned, operated and used by multiple distinct parties with diverse motivations and objectives;
there are few, if any, centralised or well-trusted entities;
devices have highly heterogeneous capabilities in particular, very many of them have scarce resources (processing power, storage, bandwidth and especially battery power may...
