# Information-Aware Secure Routing in Wireless Sensor Networks
## 6 Simulation Results
### G1 Simulations: Secure Route Construction  
Figure 5 shows the trends of packet loss ratios under different proportions of malicious nodes in our model. As we can see from the figure, the three lines share similar trends. For \(\delta\) = 20% (the blue dotted line), the packet loss ratio slowly increases from 10% to 22% in the first 10,200 s, and it suddenly jumps to 100% in the next 1200 s. For \(\delta\) = 40% (the red dashed line), the packet loss ratio slowly grows from 21% to 45% in the first 12,000 s, and then it suddenly jumps to 100% in the next 1800 s. For \(\delta\) = 60% (the yellow solid line), the packet loss ratio grows from 33% to 60% in the first 15,600 s, and it suddenly jumps to 100% in the next 2400 s. We observed that the more malicious the nodes, the higher the packet loss ratio in the WSN. The average packet loss ratio exceeds 50% when \(\delta\) = 60%, and the WSN cannot tolerate intrusions.  
In Figure 5, for \(\delta\) = 20% (the blue dotted line), the packet loss ratio suddenly jumps to 100% after 10,200 s. Because the load balance is considered in the model, nodes (especially the neighbor nodes around the sink node) in the network almost run out of energy simultaneously. Therefore, the packet loss ratio rises rapidly to 100% in the next 1200 s. The other two cases (\(\delta\) = 40% and \(\delta\) = 60%) are similar to this scenario. The model tries to ensure the load balance of the nodes in WSNs. However, a packet must pass through a limited number of nodes adjacent to the sink node to successfully reach the sink node. These adjacent nodes will run out of energy prematurely and eventually die (as shown in Figure 6). This is the \"Hot Spot\" phenomenon in WSNs.  
Figure 6a-c show the energy consumption of the 18 nodes near the sink node when the proportions of malicious nodes are 20%, 40%, and 60%, respectively.  
In Figure 6a (\(\delta=20\%\)), when the network is run to the 11,130 th second, the residual energies of all 18 nodes are less than the minimum forwarding threshold, so they cannot continue to forward packets. Thus, the packet loss ratio rises rapidly to 100%. Note that this moment basically coincides with the moment at which the blue dotted line in Figure 5 rises to 100%.  
Similarly, in Figure 6b (\(\delta=40\%\)) and Figure 6c (\(\delta=60\%\)), when the network is run to the 13,560 th second and the 16,740 th second, respectively, the residual energies of all 18 nodes are less than the minimum forwarding threshold. Note that the two moments basically coincide with the moment at which the red dashed line and the yellow solid line in Figure 5 rise to 100%, respectively.  
In summary, when the proportion of malicious nodes is 20%, the network packet loss ratio reaches the lowest level, but the packet loss ratio rises to 100% earlier than in the other two cases. In this case, each node (especially the adjacent nodes around the sink node) consumes more energy than the nodes in the other two cases, and the network uses up energy first because it can forward more packets. Therefore, network lifetime in this case is the shortest. Similarly, the packet loss ratio starts to increase earlier and rises more rapidly to 100% in \(\delta=40\%\) than in \(\delta=60\%\).  
In addition, Figure 6a-c show that some nodes (nodes 1-2 in Figure 6a, nodes 1-5 in Figure 6b, and nodes 1-10 in Figure 6c)--namely, malicious nodes set up in the simulation--consume less energy than the others. This phenomenon can be explained by two facets. First, malicious nodes are less likely to forward packets and consume a lot of energy, because the proposed model stays away from these nodes to the greatest extent possible. Second, malicious nodes forward packets selectively to economize their energy.  
Figure 5: Packet loss ratios under different proportions of malicious nodes (\(\delta=20\%\), 40%, and 60%) in information-aware secure routing (IASR).