## 5 Simulation
### System Setup  
The simulation was conducted in a multi-layer IoT setup as illustrated in Figure 3. We also included the system architecture diagram in Figure 4. In the sensing layer, an ECG monitor continuously captures health data from a patient and transmits it, along with its security metadata, to the patient's smartphone. Upon receiving the security metadata, the smartphone validates it and synchronizes the results with the cloud. We leveraged \begin{table}
\begin{tabular}{l l l} \hline \hline
**Concerns** & **Discussion Points** & **Representative Quotes** \\ \hline \multirow{6}{*}{-Cloud security. -Certificate authority (CA). -Ceri  
\begin{tabular}{l l} -TLS, channels and signatures. & \multicolumn{1}{l}{\begin{tabular}{l} “Avoiding cloud is the best thing. Cloud security is \\ contractual security...As long as you believe the contract, \\ it’s fine.” **Expert-5** \\ -Trust the cloud provider. \\ -Trusted computing. \\ -Arssuming CA with close \\ environment. \\ -Security engineering/system audits \\ \end{tabular} } & \begin{tabular}{l} “Avoiding cloud is the best thing. Cloud security is \\ contractual security...As long as you believe the contract, \\ it’s fine.” **Expert-5** \\ -I think ‘clouds’ are monitored continuously and managed \\ by professional security experts. **Expert-1** \\ -If you are actually assuming that the cloud operator is \\ malicious, you havebigger problems.” **Expert-6** \\ -However, I think it is very challenging for attackers to \\ launch side channel attacks inside the cloud right now. I think they still have very strong protection.” **Expert-3** \\ \hline \multirow{6}{*}{-Device standard and update. -Device and -Industry and Government -} & \begin{tabular}{l} “With some antivirus software on the device, we are \\ running into a very tough update issue,...as soon as any \\ kind of software decides this device is infected. We need to \\ remediation processes.” **Expert-5** \\ -Upgrade. \\ \end{tabular} & \begin{tabular}{l} “With some antivirus software on the device, we are \\ running into a very tough update issue,...as soon as any \\ kind of software decides this device is infected. We need to \\ remediation processes.” **Expert-5** \\ -Whenever you work in the health industry, you should \\ maintain a certain security, for the hardware and for the \\ software.” **Expert-7** \\ \end{tabular} \\ \hline \multirow{6}{*}{-Human centric. -Social Engineering.} & \
\begin{tabular}{l} “Hours to define a situation when somebody approaches me \\ looks like a doctor or health professional? I will believe \\ them and maybe even transfer some of the credentials or \\ they want to replace my device...” **Expert-7** \\ -law/regulation. \\ \end{tabular} &
\begin{tabular}{l} “How to define a situation when somebody approaches me \\ looks like a doctor or health professional? I will believe \\ them and maybe even transfer some of the credentials or \\ they want to replace my device...” **Expert-7** \\ -\(\ldots\)even for a secure system, the patient might not have any \\ awareness,...For example, they might simply not be able to \\ keep their phone in a safe place. Furthermore, for the doctor, \\ it will be the same.” **Expert-2** \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Concerns for system design. two innovative Python projects to effectively simulate the behaviors of both the ECG monitor and the smartphone. With the integration of Google Firebase and Vue.js, end users or inspectors can effortlessly access real-time security situational awareness of the ECG monitor via an intuitive web interface. In alignment with the experts' discussion outlined in Section 4.1, we selected the security metadata for the ECG monitor. Specifically, we utilized the program integrity hash to ensure the integrity of the running code and the measurement hash to verify the device's configuration information (as advised in Table 2, digital signature). To ensure the device's authenticity, we incorporated an attestation digital signature of the hash.