## 2 Related Works
In the healthcare domain, the need for advanced technologies is rapidly increasing, with blockchain playing a key role in the transformation of the sector [37; 38; 39]. [PERSON] et al. [3] provided an overview of blockchain-based applications in healthcare, focusing on its ability to improve electronic health records (EHR), enhance data security, and support patient monitoring and drug traceability. They emphasized blockchain ability to ensure that only authorized parties can access sensitive medical data. [PERSON] et al. [4] proposed a permissioned blockchain system that uses the Hyperledger Fabric platform to allow quick and secure access to health records during emergencies. The system enables patients to define access rules for their data, which are enforced through smart contracts. [PERSON] et al. [5] explored blockchain's potential to improve communication and security in emergency rescue operations, particularly in ambulance-to-everything communications. Their system provides secure data exchange between ambulances, hospitals, and other emergency services, preventing tampering and ensuring authenticity. [PERSON] et al. [6] designed a blockchain-based system that integrates the Internet of Vehicles and the Internet of Medical Things to enhance emergency medical responses in smart cities, allowing the real-time transmission of accident victim data to nearby healthcare services. [PERSON] et al. [7] introduced a public blockchain architecture that empowers patients to control their healthcare data while ensuring privacy and enabling secure sharing among different healthcare providers. This decentralized approach improves data access and prevents unauthorized access and tampering. [PERSON] et al. [9] proposed a system that integrates a private blockchain with IoT medical devices, using smart contracts to automate notifications for medical interventions and ensure HIPAA-compliant data handling. [PERSON] et al. [13] presented a framework designed to address security concerns by ensuring secure mutual authentication and fine-grained access control. This framework leverages blockchain's capabilities to provide confidentiality, auditability, and scalability, making it suitable for dynamic environments such as smart factories. [PERSON] et al. [12] introduced a blockchain-based system for managing audit logs among healthcare organizations, enabling interoperability and ensuring the integrity of log data. [PERSON] et al. [11] leveraged blockchain's tamper-resistant features to secure clinical trial data, using Ethereum smart contracts to automate updates and ensure data transparency using a permissioned blockchain. [PERSON] et al. [10] discussed how blockchain can address challenges in clinical research, such as data reproducibility, sharing, privacy, and patient enrollment. They emphasize blockchain's decentralized, transparent, and tamper-resistant nature, which is crucial for maintaining data integrity in clinical trials. [PERSON] et al. [8] propose a hybrid blockchain-cloud system for secure sharing of personal health data, using blockchain for transaction management and validation, while cloud storage handles large datasets. [PERSON] et al. [14] reviewed how blockchain technology was used to enhance the security and privacy of electronic health record (EHR) systems. They highlighted critical limitations of traditional EHR systems, such as data breaches, unauthorized access, and lack of transparency, and proposed that blockchain decentralization, immutability, and access control capabilities address these challenges. Practical use cases include secure patient data sharing, tamper-proof audit trails, and privacy enforcement through smart contracts. However, the study acknowledges significant barriers to adoption, including scalability, high computational costs, integration complexity, and regulatory constraints. [PERSON] et al. [16] proposed MeDShare, a blockchain-based system designed to facilitate medical data sharing in a trust-less environment.