## 5 System Design
### Private Cloud IoT System  
The proposed scheme assumes that any prevalent routing scheme, such as AODV and OLSR, is implemented, so that selecting the respective CIN can be carried out on the mobile IoT nodes, which ultimately assists in forwarding the routing information. The scheme also assumes that all the mobile IoT nodes maintain TRM to formulate its encoded address, which further enables communication with the agreement system. Additionally, the proposed scheme considers _global trust_ (_GT_) and _quality metric_ (_QM_) parameters for identifying mobile IoT nodes. The quality of service is computed by obtaining the information from the control message for route discovery by mobile IoT nodes working in an ad hoc environment. The mathematical expression for computed quality metric \(\alpha\) is as shown in Equation (1):  
\[\alpha_{i}=C_{i}\cdot A_{i}\cdot P_{i} \tag{1}\]  
As shown in Equation (1), the computed quality metric of \(i\)th node \(\alpha_{i}\) depends upon residual channel capacity \(C_{i}\), adjacent nodes of \(i\)th node \(A_{i}\), and weight of specific mobility path of \(i\)th node \(P_{i}\). Apart from this, it should be noted that computation of global trust is a representation of reliability factor based on previously exhibited behaviour of mobile IoT nodes. This is an essential security enhancement, as in case of node misbehaviour, the value of the quality metric will either rise or decline significantly. Hence, an abnormality of quality metric will be the primary indicator of misbehaved nodes in an ad hoc environment. Furthermore, it should also be noted that the value of the computed global trust fluctuates in different contexts. An attacker node can misuse this by sharing any random \(GT\) value (within the observed fluctuation) to get an illegitimate entry into the IoT ecosystem. This problem is addressed by using TRM, which assists in validating all the shared values of global trust.  
The proposed strategic game framework amends the on-demand routing by incorporating only two forms of control message, viz. (i) the first control message \(C_{msg1}\), which is required for preliminary route discovery by sharing node-based local information, and (ii) the second control message \(C_{msg2}\), which is required for forwarding a command that is exchanged in the private cloud among RIN. This control message retains the information of the selected node in order to play the role of CIN and the payoff recommended by the RIN of each node. The RIN further processes this information to confirm the node's intention towards a similar CIN. The size of both control messages is 31 bits. Figure 2a highlights the format of \(C_{msg1}\), where \(QM\) is a quality metric field while the \(GT\) field retains a global trust score. The CIN field exhibits the current role of a mobile IoT node to be a CIN. Figure 2b has fields of respective payoffs for the current CIN. As the complete operation is carried out over a private cloud system, there is no way such information could be easier to access by an attacker node. Even if the node misbehaves for this purpose, the value of each field in the control message will change, which will fail the validation process of shared information of global trust.