Lightweight and trusted sharing mechanisms for IoT data are a crucial research area focused on enabling secure, efficient, and reliable data exchange among heterogeneous IoT devices and networks. Research papers in this domain investigate frameworks and protocols that ensure data integrity, confidentiality, and authenticity while minimizing computational overhead for resource-constrained devices. Key contributions include lightweight encryption schemes, blockchain-enabled decentralized data sharing, attribute-based access control, and privacy-preserving mechanisms tailored for IoT environments. Recent studies also explore edge/fog-assisted processing, secure data aggregation, and AI-driven trust evaluation to enhance reliability and scalability. Challenges such as interoperability, latency, energy efficiency, and regulatory compliance are actively addressed to enable practical deployment. By combining lightweight security techniques with trusted frameworks, research in IoT data sharing aims to create secure, adaptive, and resilient ecosystems for real-time analytics, decision-making, and collaborative applications.