A trust structure for detection of sybil attacks in opportunistic networks

Opportunistic networks (OppNet) enable users to connect each other via wireless communication without connecting to the Internet. These networks have fragile structures and the topology of the network is changed frequently, so it is impossible to have a Trust Third Party as a certificate authority. There are many different attacks against these networks and one of them is Sybil Attack. In this paper, we proposed a new trust connection structure for Sybil attacks detection in OppNet. According to the Bayes rules and node's observation, we calculate the utility of nodes in different situations and demonstrated when nodes can trust each other. Furthermore, we considered the probability of receiving incorrect signal, in order to improve accuracy and false positive rate in the network. Results indicate that proposed algorithm improves False Positive Rate and Accuracy of the network.