In mobile ad hoc network (MANET), most of the existing routing technique lags
trusted way of communication among the mobile nodes. The control messages are also prone to
the external threats. Also, the act of performing authentication of the nodes during each routing
process causes increased overhead. Hence, in this paper, we propose a trust-based light weight
authentication routing protocol in MANET. Initially, a multipath route discovery technique is
utilised that selects the path with maximum packet success ratio as optimal path for data
transmission. For each node in the chosen path, global trust value is estimated based on direct
and indirect trust values of the node. If the trust value of any node is below threshold value, then
it is authenticated using the secret sharing technique. This authentication technique enhances the
reliability, redundancy and network lifetime. By simulation results, we show that proposed
protocol improves the reliability and security of routing