  The emergence of the Internet of Things (IoT) has resulted in a significant
increase in research on e-health. As the amount of patient data grows, it has
become increasingly challenging to protect patients' privacy. Patient data is
commonly stored in the cloud, making it difficult for users to control and
protect their information. Moreover, the recent rise in security and
surveillance breaches in the healthcare industry has highlighted the need for a
better approach to data storage and protection. Traditional models that rely on
third-party control over patients' healthcare data are no longer reliable, as
they have proven vulnerable to security breaches. To address these issues,
blockchain technology has emerged as a promising solution. Blockchain-based
protocols have the potential to provide a secure and efficient system for
e-health applications that does not require trust in third-party
intermediaries. The proposed protocol outlined in this paper uses a
blockchain-based approach to manage patient data securely and efficiently.
Unlike Bitcoin, which is primarily used for financial transactions, the
protocol described here is designed specifically for e-health applications. It
employs a consensus mechanism that is more suitable for resource constrained
IoT devices, thereby reducing network costs and increasing efficiency. The
proposed protocol also provides a privacy-preserving access control mechanism
that enables patients to have more control over their healthcare data. By
leveraging blockchain technology, the protocol ensures that only authorized
individuals can access the patient's data, which helps prevent data breaches
and other security issues. Finally, the security and privacy of the proposed
protocol are analysed to ensure that it meets the necessary standards for data
protection.
