## Dynamic Key Sharing and Fuzzy Adaptive Route Selection
### Fuzzy Adaptive Selection of Data Forwarding Routes
This control message contains the sender ID, hop-count from the BS and the energy information. When the control message is received by a node, it stores the information in the control message. The node forwards the control message after updating it by inserting its own information into the control message. This technique is particularly useful because the control message is propagated with an increasing size farther from the BS, preventing nodes around the BS from relaying heavier control messages. The cluster represented by e-CH may receive more than one instance of the control message traversing different paths from the BS to the cluster represented by e-CH. After receiving the control message, the e-CH computes the fitness of the inward paths through fuzzy inferencing. Authors in [35] propose techniques to proactively setup and maintain alternate paths in addition to the shortest path at the expense of some energy which minimize the likelihood of invoking data flooding to discover alternate paths. Low-rate data is sent along multipaths for maintaining multipaths without the need for network-wide data flooding. The \(k\)-disjoint (here \(k\) has same value as \(c\)) multipath scheme favors the cluster based en-route filtering framework as it ensure to avoid duplication of verification keys on the intermediate node and comparatively incurs lower maintenance overhead at low densities. In our scheme, since only CHs participate in data forwarding, therefore the density of the multihop inter-cluster communicating nodes is significantly lower than the actual sensor node-density in the network. Braided paths incur lesser maintenance overhead than disjoint paths. However, the use of braided paths does not favor en-route filtering scheme with distinct verification keys on the intermediate nodes on a single path. In the braid, an alternate path routes around a single shortest path node. Alternate paths are not independent, and a combination of failures on the shortest path breaks all substitute paths. They are also more prone to pattern failure [35]. Moreover, the repetition of verification keys on different verification nodes increases, and those nodes that possess distinct verification keys are likely to be left out in braided multipaths resulting in a weak en-route filtering capability. We consider that the number of votes to attach to a report is \(s=5\), and the false votes needed to drop a report is \(T_{f}=3\). We assume the number of votes required to mark a report safe is \(T_{t}~{}=~{}4\). The value of \(T_{t}\) can be set to a lower value to save energy. However, a smaller value of \(T_{t}\) implies that an attacker can compromise fewer nodes in a cluster and attach their MACs to the false report. The false report may travel all the way to the BS if \(T_{f}\) is much smaller and the number of votes attached by the compromised nodes is \(\geq T_{t}\). As soon as the value of \(T_{t}\) reaches the threshold, there is no need to further verify the same report even if the remaining votes are false, because they are not sufficient to drop a report. The value of \(s\) is chosen such that a minimum of half the cluster member nodes should endorse the report. Choosing a value of \(s>5\) is useless because either of the threshold values \(T_{f}\) or \(T_{t}\) would have been reached before the next verification node verifies the report. If the value of \(s\) is chosen to be smaller, the adversaries can easily create counterfeit reports in a few compromised nodes and attach false votes to them. \(T_{f}=1\) implies that only the FRIA attack is being considered and addressed. If we choose \(T_{f}=2\), then the attacker can compromise few nodes in the cluster and attach false votes to real reports that are dropped en-route. With a larger cluster size, the condition for picking at least  
Figure 1: Selection of data forwarding route. half the nodes to cast votes may be relaxed, because choosing more nodes to vote implies that more verification nodes are involved in the verification process.