Mobile ad-hoc network (MANET) is decentralized network, in this network nodes can move dynamically. OSI Network layer faces several attacks. Black hole attack work on highest sequence number during Replay message, a group of black hole nodes easily employed against routing in MANET called collaborative black hole attacks. When two malicious nodes cooperatively create a tunnel thereby formed worm hole attack. The proposed work focuses on trust based computing to mitigate the effects of black hole, wormhole and collaborative black hole attacks. Trust value is computed on the basis of route request, route reply and data packets. After calculation get trust values between 0 to 1. If trust value is greater than 0.5 then marks node is reliable and allow on a network otherwise block. Network performance of proposed protocol trusted secure AODV routing protocol (TSAODV) is evaluated. The result shows performance improvement as compared to standard AODV protocol.