# An Efficient Trust-Based Scheme for Secure and Quality of Service Routing in MANETs
## 2 Related Work
The idea behind this approach is to assign a trust value to each node dynamically. Due to high mobility, there should be an integration of trust and energy consumption of every node. A new trust management model was thus proposed to enhance the routing security in the network in which both direct and indirect trust values were employed in trust calculation. Final trust value is derived based on direct trust value and indirect trust value. The Bayesian probability was also used as a technique for trust management to refine the calculation of trust. The algorithm forwards packets from a source to a destination through a reliable route that also consumes less energy. [PERSON] et al. presented an algorithm in which calculated trust values are used to identify malicious nodes [18]. True flooding approach was utilized to identify attacking nodes based on trust values. This work relied on identification and avoidance of malicious nodes as well as denial-of-service attacks on the network layer based on interaction history. A route discovery algorithm was developed to discover an efficient and secure path for data forwarding by using experimental grey wolf algorithm to validate network nodes. Enhanced multi-swarm optimization was also used to optimize the identified forwarding path. It was concluded that the proposed scheme was useful in terms of secure data dissemination in scalable MANET environments. [PERSON] et al. proposed a public key management scheme using the trust graph model in this work [19]. Because of the frequent mobility of nodes, dynamic network topology, an absence of centralized administration and wireless connections, the traditional security solutions are not easily deployable in MANETs, and also the establishment of a Public Key Infrastructure (PKI) in such a dynamic network environment is a difficult task. In this regard, the authors designed a binary tree formation of the network's nodes, in order to build certificate chains between communicating nodes that are multi-hops away to avoid the clumsy problem of certificate chain discovery. Simulations of the proposed scheme under different network scenarios demonstrate that it is very effective in terms of tree formation, certificate chain establishment between nodes and join and leave occurrences to make a balance between security and performance. [PERSON] et al. proposed a Certificate distribution and a Trust based threshold revocation method. In this work, the authors developed a trust-based solution using an efficient mechanism for certificate revocation and validation by combining public key certificates [20], in order to enhance the security of the network by reducing the hazards from malicious nodes. Initially, the trust values were derived from the direct and indirect trust values and the secret key to all the nodes were distributed by a certificate authority. Followed by this, a trust based threshold revocation method is computed. Here the misbehaving nodes are eliminated. [PERSON] et al. proposed a composite trust-based public key management (CTPKM) approach with an idea of maximizing the performance of network while mitigating the vulnerabilities [21]. Based on the concept of trust, the proposed approach adopts fully distributed trust-based public key management based policy for MANETs using an easy security mechanism. This work aims to maximize performance by using trust-based approach, instead of using hard security parameters to remove security vulnerabilities. During the routing process, the nodes determine the trust of another node using a trust threshold. The results depict that CTPKM minimizes the risk at a large margin using an optimal trust threshold and maximizes the service availability with acceptable communication overhead acquired by trust and key management operations. Going through all the previous work listed, we observed that integration of QoS trust and social trust could improve the performance of routing in MANETs. Considering these notes, we combine both the types of trust components in our work.