Towards Trust-based Cognitive Networks: A Survey of Trust Management for MANETs

Managing trust in a distributed Mobile Ad Hoc Network (MANET) is challenging when collaboration or cooperation is critical to achieving mission and system goals such as reliability, availability, scalability, or reconfigurability. In defining trust and managing trust in a military MANET, we must consider the interactions between the composite cognitive, social, information and communication networks, and take into account the severe resource constraints (e.g., computing power, energy, bandwidth, time), and dynamics (e.g., topology changes, mobility, node failure, propagation channel conditions) in a military MANET. We seek to combine notions of “social trust” derived from social networks with “quality-ofservice (QoS) trust” derived from communication networks to obtain a composite trust metric. We will discuss the concept and properties of trust and derive some unique characteristics of trust in MANETs, drawing upon social notions of trust. We will give a survey of trust management schemes developed for MANETs and will discuss generally accepted classifications, potential attacks, and trust metrics in MANETs. Finally, we will suggest future research directions on trust management in MANETs based on the concept of social and cognitive networks.