A wireless sensor network is generally a vast network with large number of sensors nodes. It suffers from several constraints, like low computation capability, less storage capability, restricted energy resources, liability to physical capture, and therefore the use of insecure wireless communication channels. As the size and the density increases over the network, there are more chances of penetration of security in such network. These constraints build security in WSNs a challenge. Most of the protocols designed for wireless sensor networks consider energy efficiency but not security as a goal. In this present work, a Trust Based Secure Routing Protocol; TBSRP is designed to provide the security over the network. The presented work is a hybrid approach that performs the reliable node identification and provides the communication over the safe node. The presented work is divided in three main layers. In the first layer, the protocol level change is performed over the network. In the second layer, we have defined an authentication mechanism where Diffie – Hellman key exchange method is used to generate private and shared keys for every node in the network. At the third level of this presented work, a reliable routing approach is suggested. The trust analysis is performed here based on the honesty, reliability and the effective parameters. To demonstrate the utility of our trust based secure routing protocol, we apply it to a network having black hole attack. For each node, we identify the best trust composition and formation to maximize application performance. The presented TBSRP approach is basically an effective and reliable communication approach that can take the decision on next hop selection under the trust vector. Only a trustful node is eligible to transmit data over the network. TBSRP is compared with AODV routing protocol and the results of our work has shown that PDF is higher using TBSRP than that of AODV routing protocol.