# FarpScun: Fully Anonymous Routing Protocol with Self-Healing Capability in Unstable Sensor Networks
## 3 Fully Anonymous Routing Protocol with Self-Healing Capability
### Performance Analysis
#### 3.5.4 Simulation  
(1) Anonymous Simulation  
In this section, the position of the real sensor node that is detected by the adversary is simulated with \(Matlab\), and the result shows that the proposed protocol can effectively protect the anonymity of the sensor nodes in the communication. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Protocol** & \begin{tabular}{c} **Source Nodes** \\ **Anonymity** \\ \end{tabular} & \begin{tabular}{c} **Communications Association** \\ **Anonymity** \\ \end{tabular} & \
\begin{tabular}{c} **Destination Nodes** \\ **Anonymity** \\ \end{tabular} &
\begin{tabular}{c} **Self-Healing** \\ \end{tabular} \\ \hline \(FarpScusn\) & ✓ & ✓ & ✓ & ✓ \\ \(APR\) & \(\times\) & ✓ & \(\times\) & \(\times\) \\ \(RandomWalk\) & \(\times\) & \(\times\) & ✓ & \(\times\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Performance Analysis. In the simulation, we deploy 25 sensor nodes in an area of 1 m \(\times\) 1 m, where the positions of the four adversaries are deployed at coordinates (0,0),(0,1),(1,0),(1,1), and blind devices (normal sensors that need to guess their positions) are deployed in a square surrounded by the adversaries. We randomly generate a network topology graph from source node \(S\) to destination node \(G\) and then generate an anonymous route from \(S\) to \(G(S-A-B-G)\), as shown in Figure 7. The red dots are the deployed normal sensor nodes, and the black dots are the adversaries. We consider sensor location estimation when the sensors measure _Received Signal Strength_\((RSS)\) or \(Time-Of-Arrival~{}(TOA)\) between themselves and neighboring sensors. According to the measured \(RSS\) or \(TOA\), the adversaries can estimate the positions of sensor nodes by using the _Maximum Likelihood Estimation_(\(MLE\)). The result is that the adversary can accurately guess the actual positions of all the blind devices [25; 26], as shown in Figure 8. The blue triangle is the approximate position of the sensor node estimated by the adversary. Figure 8: Real Position of Sensor Detected by Adversary. Figure 7: Location of Sensors and Adversaries and a Randomly Generated Network Topology. If real identities are used to communicate between the sensor nodes, the adversaries may obtain the identities of the sensor nodes by intercepting the routing information, and the adversary can accurately decode the route according to the identities of the sensor nodes, and finally find the actual location of the communications sensor. For example, if the adversaries intercept the communication route \(S-A-B-G\), then they can successfully acquire the entire route, which is shown in Figure 9.  
However, the proposed protocol in this paper, while using anonymous identities to communicate, and the adversary cannot intercept the real identities of the sensor nodes, effectively solving the problem, ensures the anonymity of sensor node communication, as shown in Figure 10.  
Figure 10: The Adversities Cannot Obtain the Route. Figure 9: The Route Detected by Adversaries After Intercepting the Sensor’s True Identity. (2) Self-healing simulation  
Under normal circumstances, as shown in the figure below, a node in the S-A-B-G route has an error. If the error occurs at node B, then node S needs to restart the RREQ request in order to establish a new route to reach node G. This leads to complex process for re-connection, as shown in Figures 11 and 12. On-demand routing can find an accessible route. The destination node determines the updated topology that is based on the received message, and performs route self-healing and optimization. We discuss this in three ways. Case 1: according to discussion of Section 3.4.2, when the network topology changes, node A enters the wireless signal area of node \(C\). There is an \(A-C\) shortcut in the route \(A-B-C\), and node  
Figure 11: The Error Occurs the Node B.  
Figure 7.0 Simulation Without Self-healing Capability. \(C\) can skip \(B\) to send the data directly to \(A\).