## 4 Taxonomy of Smart Healthcare Security Solutions
### Communication Attacks  
A smart healthcare system is comprised of different IoT-enabled devices that interconnect with each to other to accomplish the shared objective. For interconnection the IoT devices have to utilize different communication protocols, such as MQTT, constrained application protocol (CoAP), hypertext transfer protocol (HTTP), extensible messaging and presence protocol (XMPP), and an advanced message queuing protocol (AMQP) that have rules and regulations that allow different IoT-based medical devices to exchange their data. However, the communication protocols are exposed to numerous security vulnerabilities, such as including SYN, flooding, and fragmentation attacks [21,94]. In this \begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline  & **Author** & **Year** & **Objective** & **4** & **5** & **6** & **7** & **8** & **Security Approach** & **OSI Layer** **Secured** \\ \hline \multirow{4}{*}{\begin{tabular}{} \end{tabular} } & [82] & 2022 & Detect malware in medical devices & No & Yes & No & No & No & Attention-based AI technique & Physical layer, network layer \\ \cline{2-10}  & [83] & 2022 & Improve the security of android wearable applications & No & Yes & Yes & No & No & Oversampling with AI models & Application layer \\ \cline{2-10}  & [84] & 2019 & Case study on Ransomware detection & No & Yes & Yes & No & Yes & Dynamic malware analysis & Network layer \\ \cline{2-10}  & [85] & 2019 & Critical analysis of ransomware on SCADA systems & No & Yes & Yes & No & No & Overshative analysis on ransomware & Network layer \\ \cline{2-10}  & [86] & 2022 & To develop a secure framework to detect ransomware in smart healthcare systems & No & Yes & Yes & No & Yes & Blockchain and machine learning-based secure framework & Network and Application layer \\ \hline \multirow{4}{*}{\begin{tabular}{} \end{tabular} } & [91] & 2022 & Detect and defend the phishing attacks & No & No & No & Yes & Equilibrium optimization with transfer function & Network layer \\ \cline{2-10}  & [92] & 2022 & Energy-Efficient phishing URL detection & No & No & No & Yes & AI and Character-level word encoding & Network layer \\ \cline{2-10}  & [93] & 2022 & Study the impact of COVID1-19 against the malicious URL attacks & No & No & No & Yes & Fuzzy logic and data mining approaches & Application and network layer \\ \hline \multirow{4}{*}{\
\begin{tabular}{} \end{tabular} } & [94] & 2022 & Develop a three factor authentication mechanism for smart healthcare system & No & No & No & Yes & Yes & Centreless user controlled single sign on authentication mechanism & Application and network layer \\ \cline{2-10}  & [95] & 2020 & Two stage authentication scheme for IoT healthcare systems & No & No & No & Yes & Yes & Physical unclonable functions & Physical, application and network layer \\ \cline{2-10}  & [96] & 2022 & To develop a static detection framework to detect privilege escalation attack & No & No & No & Yes & Yes & Static analysis using callback-based programming & Physical, application and network layer \\ \hline \multirow{4}{*}{
\begin{tabular}{} \end{tabular} } & [97] & 2020 & Proposed a self anomaly detection system for IoT-based devices & No & No & No & Yes & Yes & Proof-of-concept for anomaly detection & Network layer \\ \cline{2-10}  & [98] & 2021 & Proposed an energy-efficient and privacy preserving framework to detect MiTM attack for smart healthcare system & No & No & No & Yes & Yes & Cryptographic mechanisms & Application and network layer \\ \cline{2-10}  & [99] & 2022 & Proposed an authentication mechanism for wearable devices & No & No & No & Yes & Yes & Lightweight authentication scheme using different security phases & Application and network layer \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._subsection, we discuss the countermeasures for different communication attacks, such as MiTM, eavesdropping, impersonation, and replay attacks.