A great volume of wearable sensors, the Internet of Things (IoT), and mobile internet comprise a health service system, also called a smart healthcare system, which is ubiquitous and pervasive in contemporary hospitals. Since this healthcare system involves various medical equipment, large amounts of patient data are produced by medical devices every moment. Moreover, this patient information and clinical records are stored in single or multiple data centers, which can also bring convenience for medical professionals in disease monitoring and diagnosis.

However, attempts to invade the local servers and sell medical data or even gain access to medical devices have increased in recent years. Hence, protecting medical data security is still an urgent issue. The fragile nature of communication channels is also a severe issue for smart healthcare systems. Since a mass amount of medical data is frequently exchanged between the medical servers and sensors, the communication channel is open to eavesdropping. Therefore, assuring the authenticity, integrity, and non-repudiation of the medical data in the smart healthcare system is a serious issue.

The aim of this Special Issue is to collate original research and review articles describing advances in this field.

Potential topics include but are not limited to the following:

• Blockchain for medical data security
• Federated learning for medical data security
• Novel encryption algorithms for medical data security
• Security of medical insurance data
• Intrusion detection in internet of medical things
• New models, protocols, and applications in healthcare analytics
• Machine learning for medical data security