# Smart Contract-Enabled Secure Sharing of Health Data for a Mobile Cloud-Based E-Health System
###### Abstract  
Healthcare comprises the largest revenue and data boom markets. Sharing knowledge about healthcare is crucial for research that can help healthcare providers and patients. Several cloud-based applications have been suggested for data sharing in healthcare. However, the trustworthiness of third-party cloud providers remains unclear. The third-party dependency problem was resolved using blockchain technology. The primary objective of this growth was to replace the distributed system with a centralized one. Therefore, security is a critical requirement for protecting health records. Efforts have been made to implement blockchain technology to improve the security of this sensitive material. However, existing methods depend primarily on information obtained from medical examinations. Furthermore, they are ineffective for sharing continuously produced data streams from sensors and other monitoring devices. We propose a trustworthy access control system that uses smart contracts to achieve greater security while sharing electronic health records among various patients and healthcare providers. Our concept offers an active resolution for secure data sharing in mobility computing while protecting personal health information from potential risks. In assessing existing data sharing models, the framework valuation and protection approach recognizes increases in the practicality of lightweight access control architecture, low network expectancy, and significant levels of security and data concealment. Health Data Sharing; IoT cloud; blockchain technology; smart contracts; proof-of work; confidentiality; integrity 23 February 202315 March 202317 March 2023  
smart e-health service enables medical professionals to securely track patients, provide outpatient care at home, improve service delivery, and offer financial benefits to patients. Additionally, the availability of EHRs in clouds enables medical professionals to monitor patient health and provide adequate medical services through diagnostic and therapeutic mechanisms [4; 5; 6]. Fortunately, in addition to these benefits, the concept of data storage in EHRs has addressed various security concerns that impede the adoption of cloud-based e-health applications [6]. However, the secure sharing of health data between patients and healthcare providers remains a challenging task. Illegitimate agencies acquire intelligent methods to access EHRs without written permission, resulting in sensitive data and confidentiality breaches, as well as security attacks on e-health platforms [6]. Furthermore, patients find it difficult to monitor and manage the medical data shared in the cloud between different service providers. Consequently, it is essential to suggest effective access control strategies for platforms sharing cloud-based EHRs. Conventional methods to access and control [7; 8] the sharing of EHRs assume that requesters of cloud computing services are completely trustworthy, and allow cloud services to carry out all security controls and authorization responsibilities related to data consumption. Regrettably, this presumption no longer applies to portable clouds because they have sincere but inquisitive cloud servers. A crucial single point of failure for e-health connections can result from the fact that traditional authentication systems primarily depend on a predetermined entry point, that is, a centralized cloud server. However, compared to traditional access control methods, blockchain-based access control offers several novel security mechanisms for e-health. A blockchain creates in-alienable transaction ledgers as the first step in the intelligence sharing framework [9]. Consequently, transactions are only ever authored to the blockchain; rehabilitation behavior is not allowed. This indicates that activities documented in the blockchain cannot be changed or disrupted by any unit. This ensures a high level of reliability, stability, and credibility.