## 7 Research Directions
### Secure Service Discovery  
Smart devices can be used to perform service impersonation attacks. A malicious device can provide certain services although it does not have the required software or hardware. An adversary can configure a smart refrigerator to present itself as a medical sensor or thermostat. The goal of the adversary is to provide fake information to client devices. Similarly, in the client impersonation attack, a client device can search for particular \begin{table}
\begin{tabular}{c c c} \hline \hline
**Research Domain** & **Research Questions** & **Directions** \\ \hline \multirow{3}{*}{Service Discovery} & How can service impersonation be identified? & \multirow{3}{*}{Capability-based service advertisement and discovery (Section 7.1)} \\ \cline{2-3}  & How can malicious service discovery requests & \\  & be identified? & \\ \hline \multirow{3}{*}{Identity Privacy} & How can movement profiling for mobile IoT devices be prevented? & Use of unique device identifiers from locations-to-locations and sessions-to-sessions \\ \cline{2-3}  & How can communication relations be prevented? & (Section 7.2) \\ \cline{2-3}  & How can users control access to their sensor data & \\  & used by third-party services? & \\ \cline{2-3}  & How can privacy be preserved for sensor data & \\ \cline{2-3}  & shared with third-party services for providing & \\  & personalized services? & \\ \cline{2-3}  & How long will the data remain shared? & \\ \hline \multirow{3}{*}{Application Data Security} & How can security at the application layer & \multirow{3}{*}{Application messages can be encrypted to ensure the confidentiality of exchange messages, while the headers of the application layer protocol should be left unencrypted for protocol translation (Section 7.4)} \\ \cline{2-3}  & How can software updates be applied to & \\ \cline{2-3}  & multiple devices simultaneously that are located & \\ \cline{2-3}  & in the edge or distributed networks? & \\ \cline{2-3}  & How can smart devices be enabled to verify & \\ \cline{2-3}  & integrity and authenticity of software updates? & \\ \cline{2-3}  & How can IoT operating systems be enabled to & \\  & receive new software updates? & \\ \hline \multirow{3}{*}{Credential Security} & How can credentials stored on device memory & \multirow{3}{*}{Security schemes can be designed based on Physically Uncloneable Functions to ensure the security of the credentials embedded with smart devices (Section 7.6)} \\ \cline{2-3}  & How can confidentiality of credentials stored on & \\ \cline{2-3}  & device memory be ensured? & \\ \hline \multirow{3}{*}{Network Security} & How can anomalies on IoT networks & \multirow{3}{*}{Machine-learning-based models to identify new threats and attacks (Section 7.8)} \\ \cline{2-3}  & How can the knowledge base remain updated & \\ \cline{2-3}  & for identifying new or unseen network attacks? & \\ \cline{2-3}  & How can the optimum level of control and & \\ \cline{2-3}  & monitoring on packets be achieved? & \\ \hline \multirow{3}{*}{Digital Forensics} & How can evidence collection be enabled in the IoT environment? & \multirow{3}{*}{A Blockchain-based distributed and decentralized network to maintain a chain of custody of the evidence and avoid single points of failures on storage media (Section 7.9)} \\ \cline{2-3}  & How can verification of authenticity and integrity of evidence during an investigation & \\ \cline{2-3}  & be enabled? & \\ \hline \hline \end{tabular}
\end{table} 
Table 13: Research problems and guidelines. services, although it does not have capabilities to interact with the services, and understand information returned by a service device. One of the goals of an attacker is to force target devices to process discovery messages. A mobile application that is designed to interact with smart home appliances can be malicious to discover and communicate with medical sensors located in the home network. The mobile application can send malformed requests to the medical sensors.