The recent advancements in federated learning (FL) and related technologies have significantly enhanced privacy, security, and efficiency in decentralized data processing. A notable trend is the integration of hardware-based security mechanisms, such as exclaves and TrustZone, to ensure the integrity and transparency of FL processes. These innovations address critical vulnerabilities, including backdoor attacks and gradient leakage, by implementing novel defense strategies and model transformations. Additionally, the use of local differential privacy (LDP) has been extended to federated heavy hitter analytics, offering a robust solution for privacy-preserving data collection and analysis. In the realm of real-time applications, fall detection systems leveraging smartphone accelerometers and Wi-Fi CSI have shown exceptional accuracy and energy efficiency, marking a promising direction for eldercare technologies. Overall, the field is progressing towards more secure, efficient, and privacy-conscious solutions, with a strong emphasis on practical implementation and measurable performance improvements.