## 3 System Model and Methodology  
We aim to empower users to communicate efficiently while maintaining control over their personal information, thereby fostering trust and privacy in OMSNs. Trust and privacy are indeed closely related but distinct concepts. Trust is a measure of confidence in an entity's behavior based on past interactions and social relationships. It is context-dependent and can vary across different spheres of interaction, such as personal, professional, or social. In OMSNs, trust is quantified using social metrics that help to establish the likelihood that a node will reliably forward a message without compromising the sender's intentions. Trust can be asymmetric; for example, node A may trust node B more than node B trusts node A, depending on their interaction history. On the other hand, privacy concerns the control over the dissemination of personal information and the ability to communicate without exposing sensitive data to unintended parties. Therefore, privacy-aware routing protocols aim to ensure that messages are forwarded in a manner that respects the sender's privacy preferences, which may include restricting the visibility of messages to certain nodes based on trust levels. Our approach considers contextual trust differentiation by using trust thresholds and relationship scores to determine the next hop for message forwarding. For example, trusting a friend socially but not professionally illustrates this concept of contextual trust. This would mean trust metrics could differ for various contexts (e.g., work, social, family). Thus, if a node is trusted in a social context but not a professional one, the trust metrics can be adjusted accordingly to prevent message propagation through that node in a work-related context. Consequently, we propose that the privacy-aware forwarding modes consider the context of the network and the relationships between nodes. This implies introducing an overarching context layer that sets parameters for different scenarios, such as work or home. Users could define their privacy preferences for various contexts, and the system would use these settings to make routing decisions that align with the desired level of privacy. Figure 1 presents our system model to empower privacy in OMSNs. For example, if you are part of a professional network and another social network, you might set higher trust thresholds for message forwarding within your professional network. This would ensure that only nodes (colleagues) with a strong professional trust relationship with you would be selected to forward sensitive work-related messages. Conversely, you might opt for a lower trust threshold for social messages, allowing more nodes (friends) to participate in forwarding nonsensitive messages. For efficiency purposes, the proposed privacy-aware solution is integrated into existing routing algorithms without affecting the overall path construction logic; thereby, users have the flexibility to define their privacy needs in various social contexts, which would be respected during the message-forwarding process. Figure 1: System model overview. To implement this model-enhancing privacy in OMSNs, the methodology shall provide a comprehensive approach from conceptualization to validation. Therefore, our methodology can be distilled into three clear steps: (1) privacy-aware mode development, (2) simulation and implementation, and (3) evaluation and performance study. The first phase involves the creation of a theoretical framework that defines the privacy challenges and formulates the privacy-aware forwarding strategies. It includes developing trust models and algorithms that will enable nodes within the network to make informed decisions about message forwarding based on predefined privacy preferences. The formulated strategies are translated into practical algorithms and implemented within a simulated OMSN environment in the second phase. This step is critical for testing the feasibility and effectiveness of the privacy-aware forwarding strategies under controlled conditions.