# Efficient and Secure EMR Storage and Sharing Scheme Based on Hyperledger Fabric and IPFS
## 2 Related Work  
There are already numerous solutions based on blockchain technology that address the issues of secure storage or the sharing of medical data. [PERSON] et al. [7] proposed an EMR management scheme that combines cloud and blockchain technologies, which ensures the secure storage of EMR. However, it does not address the implementation of secure data sharing. [PERSON] et al. [8] proposed an EMR sharing scheme that integrates Ethereum blockchain and cloud computing networks, but it does not fully address privacy concerns. [PERSON] et al. [9] proposed recording the operations of various stages of EMR on the blockchain to ensure traceability and tamper resistance. [PERSON] et al. [10] proposed ensuring the security of data stored in the cloud through access permissions and effectively tracking and monitoring all operations on the data using smart contracts. [PERSON]. [9; 10] suggested that monitoring and recording the process of medical record operations can prevent tampering with the records, but they cannot prevent the leakage of patient privacy. [PERSON] et al. [11] encrypted medical data using interleaved coding techniques, effectively protecting personal privacy. [PERSON] et al. [12] proposed a blockchain-based medical data sharing scheme, integrating searchable encryption and proxy re-encryption to achieve secure sharing. [PERSON] et al. [13] introduced the Ancile framework, which transfers the ownership and control of EMR to data owners via the Ethereum platform and effectively ensures the information security of EMR through proxy re-encryption technology. [PERSON] et al. [14] proposed a secure and efficient data management framework based on Ethereum, utilizing edge computing and blockchain to ensure data security and privacy. [PERSON]. [15] combined searchable encryption algorithms to construct index expressions for EMR data and stored them on the blockchain, allowing data owners to control access permissions for their data. [PERSON] et al. [16] introduced MedRec, an EMR sharing scheme, employing three Ethereum smart contracts to implement fine-grained access control for patients' medical records, enabling third-party users to access data upon successful authentication. These approaches [12; 13; 14; 15; 16] safeguard data security and protect patient privacy through access control. However, the systems proposed are implemented on Ethereum, where normal transactions require a certain amount of tokens and additional gas expenses, thus increasing system complexity and management costs, which may not be entirely suitable for hospital information systems. With the evolution of blockchain technology, there have been research efforts adopting the more lightweight Hyperledger Fabric [17] architecture to implement the blockchain network component of the designed systems. Hyperledger Fabric is one of the widely adopted solutions in the current realm of consortium blockchains [18]. It integrates a member man agement service mechanism, allowing multiple organizational entities to participate in and manage it jointly. Moreover, this solution supports smart contract development in various common programming languages, exhibiting greater flexibility in practical deployment and application. [PERSON] et al. [19] proposed an access control policy algorithm aimed at enhancing data accessibility among healthcare providers, enabling the implementation of an EMR sharing system based on Hyperledger Fabric. However, they did not discuss the data integrity aspect of the solution. [PERSON]. [20] used Hyperledger Fabric to enhance interoperability among healthcare institutions and to solve the fragmentation problem. Table 1 summarizes the limitations of related work and explains how this study addresses these shortcomings. In addition to the issues mentioned in the table, most related work does not separate ownership information from the specific medical data of patients. This makes it difficult to prevent privacy threats from data mining that could reveal patient identities.