Cooperation enforcement schemes for MANETs: a survey

The employment of adequate trust methods in mobile ad hoc networks (MANET) has been receiving increasing attention during the last few years, and several trust and security establishment solutions that rely on cryptographic and hashing schemes have been proposed. These schemes, although effective, produce significant processing and communication overheads and consume energy, and, hence, they do not take into account the idiosyncrasies of a MANET. More recently, cooperation enforcement methods have been proposed for trust establishment in MANET. These schemes, classified as reputation-based and credit-based, are considered suitable for ad hoc networks, where key or certificate distribution centers are absent or ephemerally present, and for networks that consist of devices with limited processing, battery, and memory resources. Cooperation enforcement methods do not provide strong authentication of entities. Instead, they contribute to the identification of the trustworthiness of peers and to the enforcement cooperation using mutual incentives. This paper surveys the most important cooperation enforcement methods that have been introduced, providing a comprehensive comparison between the different proposed schemes. Copyright # 2006 John Wiley & Sons, Ltd.