## 6 Evaluation of the Proposed Security Improvement Framework (SIF)  
In this office security system, employees used their identity card to enter the office premises and individual's room. The router that reads the identity card sends the information to the coordinator at 500 ms delay. If any hacker tries to do a Flooding Attack, then this system can detect and protect against it. To evaluate the flooding probability of the office security system, we have sent a bunch of messages from router to coordinator. Coordinator reads the messages at 200 ms delay and counts the messages which are coming simultaneously. We have plotted flooding probability curves for the office security system with respect to the number of messages and delays, as shown in Figure 7. This plot indicates that for a number of messages greater than 7, flooding probability is 1. If the Security Improvement \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \(P_{1}\) & \(P_{2}\) & \(P_{3}\) & \(P_{4}\) \\ \hline CRF & 2 & 5 & 8 & 12 \\ Normalized (\%) & 16.66 & 41.65 & 66.67 & 100 \\ QoP Partition & Low (\(<\)50\%) & Medium (50–80\%) & High (\(>\)80\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 10: QoP partition based on Cumulative Reward Function (CRF). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Authentication** & **Confidentiality** & **Data** & **Availability** & **Privacy** \\  & **(s1)** & **(s2)** & **Integrity (s3)** & **(s4)** & **(s5)** \\ \hline KY AES Encryption Key & 1 & 0 & 0 & 0 & 1 \\ \hline Physical Attack Detection & 0 & 0 & 0 & 2 & 1 \\ \hline Replay Attack Prevention & 1 & 1 & 0 & 0 & 1 \\ \hline Flooding Attack Prevention & 1 & 1 & 1 & 0 & 1 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Numeric reward matrix. Framework (SIM) gets more than 7 messages simultaneously at a receiving delay of 200 ms, then it decides flooding occurs. To confirm the presence of the router itself in the network, it sends an encrypted Pulse Beat signal to the coordinator every 200 ms. The coordinator, in its turn, decrypts the Pulse Beat message. When the router becomes hacked or the coordinator does not receive any Pulse Beat signal from the router within 2 s, the coordinator makes an Http Request to the web application that shows Physical Attack status (Yes/No) to the admin. We turned the router off several times and checked the status signal. Every time, the system was able to detect the Physical Attack successfully. Security solutions always have negative impacts on network performance and users' Quality of Service (QoS) guarantees. Security solutions need to transport users' certification to verify identity and to encrypt data for confidentiality. These increase transmission delays, which results in lowering system throughput and quality of service. Moreover, complex security mechanisms always add to the cost of performance much more, especially in resource restrictions. Therefore, in order to provide multilevel security service in the SIF to the users, it is insufficient to take security benefits into consideration only; adequately analyzing the impact of all the security policies on performance quantitatively is also necessary. The average signaling delay for each security policy is shown in Figure 8. It is observed that, in general, performance degrades as security policies provide more benefits. Maximum Signaling Delay is 1200 ms, which satisfies the real-time applications. Figure 8: Signaling delay in each security policy of the proposed SIF. Figure 7: The Flooding Probability curve with respect to number of messages and delays. Among three proposed Security Policies (\(P_{2}\), \(P_{3}\), \(P_{4}\)), \(P_{4}\) performs more signaling delays than the others. Security Policy \(P_{4}\) includes solutions of three potential security threats (Physical, Replay, and Flooding Attacks). Therefore, it requires more time to send the signal.