# A Hyperledger Fabric-Based System Framework for Healthcare Data Management
## 3 Existing Frameworks  
Existing research regarding the applications of blockchain technology in the healthcare field mainly includes information protection, payment, data storage and sharing, data transactions, and drug traceability. The related works are as follows:  
In 2015, [PERSON], [PERSON], and [PERSON] combined blockchain and off-chain storage to build a personal data management platform [25]. The privacy concerns were resolved by allowing users to manage access permissions. This study has certain reference significance as healthcare data is also a kind of personal data. However, in some cases, the patient does not have enough medical knowledge to address the permissions, so it is inappropriate to completely manage permissions by patients. In 2016, MedRec was developed based on Ethereum's smart contracts which connected healthcare providers, allowing comprehensive and credible medical history data to be shared across different institutions [8]. The Healthcare Data Gateway (HDG) combined a traditional database and gateway to manage personal electronic medical data on the blockchain, ensuring security and privacy through access control and secure multi-part computing [26]. As a result, the combination of blockchain and other security technologies can strengthen the protection of patient privacy. It should be noted that the basis for those methods to deal with the ownership of medical data is that the data is completely controlled by the patient. However, this assumption is not in compliance with Australian law which requires medical records be retained for a minimum of seven years by healthcare providers. On the other hand, whether the ownership of medical data only belongs to patients is still worth discussing. In 2017, more researchers started to look into cloud storage and permissioned blockchain. [PERSON] et al. presented a blockchain data sharing framework for the primary care of oncology patients from the medical practice perspective where privacy is protected through symmetric encryption and there are no incentives for malicious behavior [27]. BBDS employed encryption and digital signatures to ensure access control [28]. MeDShare is a data-sharing model between cloud providers using blockchain, where the protection of privacy is demonstrated in access control and the trace of violations [29]. With the introduction of cloud computing, the feasibility of blockchain applications has increased but security issues have become more complex. In 2018, Ancile utilized smart contracts in Ethereum for access control and interoperability of electronic health records which focused on the ownership rights of patients and proposed the proxy re-encryption method to store private keys remotely [30]. FHIRChain demonstrated a standards-based architecture to ensure secure and scalable clinical data sharing in a blockchain environment, which ensured privacy by keeping sensitive data off-chain and exchanging reference pointers on the chain [31]. [PERSON] et al. proposed a Hyperledger Fabric data sharing scheme in mobile healthcare applications in which data sharing and accessing are determined by the users [32]. In [PERSON] and [PERSON]'s scheme, privacy is achieved from patient-driven interoperability in healthcare [6]. The above research still attempted to achieve privacy-preservation through patient-driven access control policy but are lacking solutions for third-party security issues. Moreover, patient-driven access control is difficult to convert from the existing model because it increases the difficulty of data management for doctors, clinics, and hospitals without any obvious rewards. In 2019, [PERSON] et al. proposed EHRs sharing scheme that was based on the blockchain and suggested that in the healthcare data sharing process, blockchain only acts as a trust mechanism and privacy issues should be completely revolved by a third party [33].