Effective trust and reputation scheme for securing Mobile Ad hoc routing

Abstract

Trusted path ensures packet delivery and reduces the packet dropping which results in a saving of bandwidth and energy of the mobile node. Trust path finding mechanism has been proposed in the literature based on direct and indirect observations and applying Bayesian theory, Dempster-Shafer theory involving probability logic. In this research, we studied trust computation problem with predefined fixed movement and random movement (frMANET) to compute trust. Our scheme(frMANET scheme) is based on state of the art subjective logic based belief model involving uncertainty in behavior. We use consensus for parallel paths and discounting for transitive paths to get over bad mouthing and ballot stuffing. Unlike trust management in a conventional scheme that computes trust based on packet dropping and forwarding, we have added a parameter - state of the node indicating priority work and unable to participate notification. We have used public key based digital signature to assert nonrepudiation for the nodes who deny the fact that they are continuously sending positive or negative opinions leading to bad mouthing and ballot stuffing. Unlike trust management in a conventional scheme that computes trust based on packet dropping and forwarding, we have added a parameter state of node indicating priority work and unable to participate notification. We include service rating as well considering file sharing and file downloading as service rating parameter. We have evaluated University case study of a course offered by a professor in university to the enrolled and not enrolled students. The simulation results show an increase in packet delivery ratio with marginal overhead in average message transmission. The scheme helps in avoiding unnecessary fluctuations in trust values of trustworthy nodes, less computational overhead. newline newline