# Data Privacy in the Internet of Things: A Perspective of Personal Data Store-Based Approaches
## 4 PDS-Based Solution for IoT Privacy
### PDS-Based Solution for Privacy Threats  
We propose the FoT-PDS [67] as an extension of the FoT paradigm, specifically addressing data privacy concerns. We extend the FoT paradigm by introducing a novel data management strategy to deal with data privacy challenges within the IoT landscape. We advocate adopting PDSs as the storage mechanism and leveraging its associated benefits. We argue that the PDS serves as a solution to mitigate privacy issues in the IoT. We based our proposal on the use of PDSs distributed across multiple layers. Accordingly, we incorporate storage mechanisms in FoT-PDS-Servers and Cloud-PDS-Server layers. Each has a PDS instance, empowering users to control and manage how, what, who, and when their data can be accessed, processed, and disclosed. The literature includes studies exploring Personal Data Stores (PDSs) as a promising solution to address privacy concerns related to personal data from different perspectives. [PERSON] et al. [56] introduced the PDS concept to promote user autonomy, allowing people to store their data in private locations and decide when and with whom to share it. Later, [PERSON] et al. [68] expanded the idea with My Data Store, providing a framework for managing heterogeneous data collected by various applications and sensors within a trusted application ecosystem. These approaches prioritize privacy by giving users direct control over their data. [PERSON] et al. [57] analyze the impact of PDSs on personal data protection, highlighting how these systems can promote privacy by aligning with individual rights and legal bases for data processing. They examine how PDSs can help reduce online surveillance practices and address information asymmetries between individuals and large organizations. However, the authors also identify limitations, noting that many digital privacy challenges remain even with PDSs, such as ensuring complete protection against monitoring and misuse of personal data. [PERSON] [69] explores how decentralized technologies and Semantic Web standards can enhance communication between data subjects and controllers, enabling individuals to understand their rights and make decisions about their data. She proposes a digital interface to facilitate privacy term negotiation and access governance, helping individuals exercise \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Criterion** & **Centralized Systems** & **PDS Solutions** \\ \hline User Control & Low—data are managed by third parties & High—users define access and usage policies \\ \hline Privacy Risk & High—single points of failure and uncontrolled data reuse & Low—user-centric control and distributed access \\ \hline Computational Overhead & Low—cloud-based processing at scale & Medium to High—some rely on local or distributed processing \\ \hline Monetization Capability & Absent—user data monetized by providers & Possible—some PDS platforms support data sharing with compensation \\ \hline Transparency & Limited—access and processing logs are not always available & Moderate to High—PDS can provide dashboards, logs, and audit tools \\ \hline Scalability & High—mature and consolidated architectures & Variable—depends on platform design (local/cloud, centralized/decentralized) \\ \hline User Experience & High—refined and integrated interfaces & Medium—usability remains a challenge for broader adoption \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparison between traditional centralized systems and PDS-based approaches. their GDPR-based rights. This approach ensures that privacy information is accessible and understandable, making the exercise of user rights more effective and transparent. [PERSON] et al. [70] developed TIDAL, a Solid-based application that allows citizens and researchers to collaborate on health research projects ethically and transparently. TIDAL stores data in individual Solid pods, where each user controls what is shared with researchers, maintaining a high level of privacy. Specifically in the IoT context, [PERSON] et al.