# Design and Implementation of a Contextual-Based Continuous Authentication Framework for Smart Homes
## 2 Related Work
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**No.** & **Utilized Information** & **Advantages** & **Limitations** \\ \hline
[8] & Location and e-receipt & Provides authentication model for mobile environments & Only includes location and e-receipt as contextual information based on the user’s presence \\ \hline
[9] & Location, time and operating system processes & Provides context-aware authentication and implementation & Only uses GPS location, which will not be available in most cases, especially indoors \\ \hline
[21] & SMS & Provides transparent and continuous authentication in addition to implementation & SMS function is ignored and replaced with apps that achieve the same purpose. \\ \hline
[29] & Calls, SMS and GPS based location. & Enables implicit and continuous authentication & Only uses GPS location, which will not be available in most cases, especially indoors. In addition, SMS and calling functions are ignored and replaced with apps that achieve the same purpose. \\ \hline
[30] & SMS, calls and geographic location & Provides implicit continuous authentication & SMS and calling functions are ignored and replaced with apps that achieve the same purpose. Only used GPS coordinates collected, which will not be available in most cases, especially indoors. \\ \hline
[31] & Telephone calls and SMS & Provides illegitimate user detection & SMS and calling functions are ignored and replaced with apps that achieve the same purpose. \\ \hline
[32] & Wearable clothing colors & Provides continuous user authentication & Unsuitable, for example, in an environment with a uniform clothing style; also restricts users to a specific type of clothing whenever they want to access the desired service. \\ \hline
[34] & Small hardware tokens & Provides continuous authentication based on the user’s presence & Limits access to the use of location-based contexts \\ \hline
[35] & Hardware token (RFID tags) location and profile & Perform authentication and access control approach in a very flexible and scalable model & Limited to only using locations and profiles; also does not provide any implementation or evaluation of the proposed framework. \\ \hline
[36] & Location & Provides an analysis of the requirements of the design and implementation & Only uses Wi-Fi based location; no evaluation is provided. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: A comparison of some relevant related works. unsuitable, for example, in an environment with a uniform clothing style and also restricts users to a specific type of clothing whenever they want to access the desired service. A continuous authentication method for wearable wireless devices is suggested in [33]. Taking into account that such devices are susceptible to theft or loss, this approach is impractical for mobile users. In [34], a transient authentication mechanism is proposed for user authentication through small hardware tokens, limiting access to the use of location-based contexts. A contextual attribute authentication model for mobile environments is defined in [8]. However, this model only includes location and e-receipt as contextual information. Even though the authors in [35] provide a context security approach, the proposed scheme is limited to only using locations and profiles. Furthermore, it does not provide an implementation and evaluation of the proposed framework. A Wi-Fi-based IoT smart home system is depicted in [36], and includes the requirements of the design and implementation. As an example, the proposed system provides user access and configures and controls the system with an easy user interface running on mobile devices. However, it does not involve contextual information for the authentication process. Our work differs from the aforementioned solutions in several ways. It not only depends on static credentials or tokens but also on available contextual information such as location, calendar and profile.