<p>In recent years, social media has become a significant part of everyday life and has significantly transformed how people communicate. However, this widespread adoption generates substantial concerns regarding the privacy and security of user data. To address these challenges, this paper proposes a novel framework, BEHSMD (blockchain-enhanced Handle System for secure social media data), which integrates blockchain with the Handle System to provide persistent identifiers (PID) for the users and contents. The proposed model uses smart contracts to enforce the data access policies and a hybrid cryptography scheme to achieve fine-grained access control and secure data sharing. In addition, we introduced MEOMPA (a mix of the Equilibrium Optimizer and Marine Predators Algorithm) to enhance the security of systems and content. Finally, the architecture embeds a transformer-based machine learning model for real-time content moderation, using security-aware loss functions and persistent identifiers to enable traceability and accountability. Experimental results show that BEHSMD acquires efficient encryption, decryption, and key generation times. The findings indicate that the proposed mechanism is a scalable, auditable, practical, and privacy-preserving framework for sensitive data management on social media.</p>