1. Introduction

With the rapid development of emerging information technologies, the integration of various information technologies with the medical industry has become an inevitable trend. According to the "Opinions on Promoting the High-Quality Development of Public Hospitals" issued by the General Office of the State Council of China, the opinion proposes to fully integrate informatization into the high-quality development of public hospitals and strengthen the supporting role of informatization. The informatization of healthcare is the inevitable path to the modernization of China's healthcare and an important direction for healthcare construction. Among them, the Electronic Medical Record (EMR) system is valued and has become an indispensable part of medical services because it can provide high-quality medical services and reduce medical costs [1]. At the same time, its importance in medical data analysis cannot be ignored. During the COVID-19 pandemic, EMR datasets played a positive role [2]. With the surge in demand for medical services, more and more medical institutions are using EMR systems to replace paper medical records, which has promoted the development and application of medical information systems and also greatly increased the security risks of medical information storage.

The EMR (Electronic Medical Records) systems contain a vast amount of patient privacy data, and the structure and format of the data are not standardized [3]. Additionally, different institutions implement various management methods, leading to difficulties in the interoperability of medical data among different medical or insurance institutions, creating a serious “data island” issue [4]. Some patients share their medical data through cloud servers or applications, but the cloud servers provided by third-party vendors are semi-trustworthy, and they may steal or tamper with user data. Moreover, traditional EMRs store medical data on private or cloud servers, exposing the system to risks of malicious attacks, data breaches, and tampering, with the potential loss of private medical data. Therefore, reducing the security risks of medical information systems is crucial for personal privacy and social welfare.

Blockchain technology, characterized by its decentralization, high trustworthiness, traceability, and immutability, meets the secure and reliable needs of complex medical scenarios [5]. In recent years, blockchain has garnered widespread attention in the medical field.

2. Relevant Theories

2.1. Understanding Blockchain Technology

Based on asymmetric encryption algorithms, blockchain technology is an advanced technology. Blockchain uses a modified version of the Merkle tree data structure, combined with consensus mechanisms, peer-to-peer networks and smart contracts, amongst others, to create a distributed database technology. The system ensures that all records are immutable as trusted or semi-trusted nodes maintain an ever-growing chain through consensus mechanisms. The process relies on cryptographic means such as hashing, digital certificates and signatures to ensure the authenticity and security of records, rather than requiring central control. Therefore, blockchain naturally has the characteristics of decentralisation, high trustworthiness, traceability and immutability.

Blockchains, depending on their access and management rights, can be divided into public and private blockchains. In public blockchains, any participant can take part in the transaction and data consensus process, such as Ethereum, while private blockchains are closed networks that only allow highly trusted nodes to verify transactions and are only open to specific groups, such as Hyperledger Fabric. Traditional consensus mechanisms, such as Proof of Work (PoW) and Proof of Stake (PoS), typically require multiple block confirmations to be completed, which inevitably leads to efficiency issues. Private blockchains, represented by Hyperledger Fabric, use Practical Byzantine Fault Tolerance (PBFT) to solve the fast confirmation problem, improving consensus efficiency.

In addition, private blockchains are based on partial trust between participants, improving performance; use high-performance nodes as core nodes, reducing the need for each node to participate in full processing, improving scalability; restrict user access and transaction activity, improving stability; and can be modularly adapted to different needs, providing greater flexibility. Therefore, private blockchains are more suitable for the needs of medical data sharing [6].

2.2. Theories of Data Encryption and Cybersecurity

Attribute-Based Encryption (ABE) is highly beneficial for medical data as it allows for fine-grained access control. There are two primary encryption methods within ABE: Key Policy ABE (KP-ABE) and Ciphertext Policy ABE (CP-ABE). In KP-ABE, the user's private key is bound to a well-defined access structure, while the encrypted ciphertext is associated with a set of specific attributes. Only if these attributes match the requirements of the access structure in the private key can a user decrypt the corresponding ciphertext. This means that which ciphertexts a user can decrypt is determined by the access structure in the private key.

Conversely, in CP-ABE, the user's private key is associated with a set of attributes and the ciphertext is encrypted in accordance with a specific access policy. To successfully decrypt the information, a user must have a set of attributes that satisfy the requirements of the ciphertext's access policy. Therefore, in a KP-ABE system, it is the access policy of the ciphertext that is the determinant of which users have decryption rights.

In essence, KP-ABE emphasises how a user's private key determines which messages they can access, while CP-ABE emphasises how the access policy of the ciphertext controls which users can read the information [7]. Each method provides a flexible and robust solution for attribute-based data protection, each with its own characteristics and application scenarios.

Attribute-Based Encryption (ABE) provides one-to-many encryption and decryption capabilities that differentiate it from traditional public key encryption technologies such as Identity-Based Encryption. An ABE system doesn't need to know the specific identity of the recipient during decryption, unlike Identity-Based Encryption. Instead, ABE treats an individual's identity as a set of attributes and allows decryption only if the user's set of attributes meets the conditions defined at the time of encryption. As a result, access to data can be restricted on the basis of user attributes such as roles, departments or permissions. In the healthcare sector, this ensures that only authorised personnel can access sensitive health information. This approach provides greater flexibility and adaptability for encrypted communications.

2.3. Decentralization in Data Security

Blockchain networks can handle any type of digital transaction, with the size of the transaction depending on the data type involved. In our application, the network needs to process patient health-related data that may exist in formats such as word processing documents, scanned images, PDF reports, CD images, video files, or plain text. If all these types of data were to be stored on-chain within the blockchain network, it could lead to scalability issues. As the blockchain network grows, storage bottlenecks may arise. The system might struggle to handle the storage demands, as the size of the blockchain network could grow exponentially. Issues related to storage capacity could lead to scalability challenges for the system. Moreover, each full node might have a complete ledger copy, leading to file redundancy within the network and further space consumption. These limitations necessitate offloading data to off-chain storage systems that overcome space and scalability constraints.

In traditional network architectures, offline file storage would be accomplished within centralized file storage systems, possibly dedicated file servers or multiple file servers for different applications. For decentralized systems like blockchain applications, the concept of a centralized file system may not be applicable, as it contradicts the purpose of a distributed architecture. If a centralized file server were used in a blockchain application, it would become vulnerable to attacks and a single point of failure. For this reason, the file system used for such applications should also be decentralised in order to ensure the security and efficiency of the system.

IPFS, an acronym for InterPlanetary File System, is designed to decentralise file storage by using content addressing to identify files linked across a global network of computing nodes. As a peer-to-peer network protocol, IPFS works without a central server that takes care of the storage, retrieval and distribution of the data. Similar to BitTorrent, nodes on the network can publish new content or retrieve existing content from distributed storage. A distributed hash table (DHT) is used to address content, facilitating search and retrieval of distributed files. IPFS is a secure, high-throughput, content-addressable system that uses a block-based storage model to store large amounts of data.

Content addressability is achieved by assigning a unique hash address to each file uploaded to IPFS. This ensures consistency of the file hash addresses stored across all nodes in the system, as the same file will receive the same hash address if it is uploaded multiple times. The use of IPFS within a blockchain architecture for storage allows the network to remain traceable, in addition to reducing dependence on complete nodes. IPFS is capable of storing any type of digital transaction and is applicable to a multitude of applications. Its deduplication mechanism effectively addresses the issue of data redundancy in decentralized systems.

The integration of decentralization and deduplication enhances system efficiency and reduces the waste of storage space. In blockchain networks, nodes only contain the hash addresses of data in transactions, not the data itself, which allows new nodes to join or rejoin the network after a pause more quickly. The off-chain storage integration of IPFS addresses the scalability limitations faced by blockchain networks due to storage issues. Data is also permanently stored in the IPFS network, ensuring its tamper-resistance and security [8].

The architecture of IPFS includes four main components to ensure high performance, high throughput, security, and low cost. These components are: Distributed Hash Table (DHT), Self-certifying File System (SFS), BitSwap protocol, and Merkle DAG structure. As shown in Figure 1, working together, these components make IPFS a powerful decentralized storage solution.

Figure 1: IPFS Components (Photo/Picture credit: Original).

3. System Analysis and Application Research

3.1. Analysis of Existing Medical Information Systems

Today's patients expect a more personalized, fluid and coordinated care experience [9]. To accomplish this, healthcare providers must integrate health information from multiple, isolated data sources - including medical records, payment systems, genomics, clinical trials, and government websites - in order to make diagnoses. However, two major issues limit this integrated approach: first, the significant security and privacy concerns associated with sharing health records; and second, the fragmentation of information as a result of patient interactions with numerous healthcare providers [10].

Recent high-profile incidents of medical record security breaches have heightened concerns about data security and patient privacy. A recent study reveals that the scale of healthcare data breaches and their impact on healthcare organizations and patients is growing rapidly. Patients are most concerned that they have little or no control over their information once it is made available to payers, providers, or healthcare exchanges. Patients want a clearer picture of how their data is being used, who has access to it, and when it is being modified.

In addition, patients' medical histories involve multiple caregivers, including pediatricians, dentists, employer health plan providers, or medical specialists. Over time, they leave a trail of data across multiple healthcare systems that enclose data in siloed repositories. This results in a trail of health records that are difficult to collect, difficult to piece together, and largely owned by healthcare providers. Table 1 summarizes other current pain points in healthcare and potential applications of blockchain technology.

Table 1: Pain Points in Traditional Healthcare Information Systems and Potential Opportunities in Blockchain.

Efficiency in healthcare is in dire need of improvement. Currently, a large number of medical records are still stored in paper form and scattered, which limits their use in coordinating care, evaluating the quality of services or reducing medical errors. While healthcare data has begun to be collected digitally in various locations, the key is to extract maximum value from this data while avoiding an overly complex process. One of the main challenges facing the healthcare industry is how to record and store information easily and economically, as well as ensure secure sharing across different applications and systems [11]. It is also crucial to ensure portability and compatibility of data across different systems [12].

3.2. Blockchain Application in Healthcare: Case Studies

Blockchain technology, with its cutting-edge capabilities, is revolutionizing the healthcare sector. Its successful implementation has paved the way for seamless and efficient data sharing among key network participants and healthcare providers. This collaborative environment is fostering the development of cost-effective treatments and advanced therapies for a multitude of diseases, setting the stage for a surge in healthcare innovation in the years ahead.

This technology is instrumental in enhancing the quality of life by being at the forefront of digital transformation and innovation. It offers a plethora of significant opportunities for the healthcare industry, fostering stronger connections between medical professionals and patients [13]. In the next section, Table 2, we will explore some of the key applications of blockchain in the healthcare landscape.

Table 2: Key applications Blockchain for healthcare.

Blockchain technology stands as a revolutionary ledger system that meticulously documents transactions in a decentralized manner, transcending traditional healthcare management structures. Its precision and simplicity streamline processes, yielding time and cost savings, thereby reducing managerial burdens [13]. A paramount challenge within the healthcare sector is the unauthorized disclosure of sensitive data, often exploited for nefarious purposes. Blockchain's robust security measures offer a swift resolution to this issue, safeguarding critical information against misuse.

Furthermore, Blockchain facilitates real-time access to up-to-date and verifiable patient records, enhancing the accuracy of medical evaluations [14]. The potential of Blockchain in healthcare is immensely promising, as it addresses some of the most urgent problems plaguing the industry. By integrating therapy providers and ancillary services into a unified network, Blockchain ensures uniform data availability. The adoption of Blockchain technologies promises substantial advantages for the healthcare business ecosystem.

4. Discussion

4.1. Evaluating Blockchain in Medical Information Security

4.1.1. Enhanced Health Data Accuracy through Blockchain

The integration of blockchain technology in healthcare data management systems offers a transformative approach to patient medical data. Traditionally, a patient’s health records are scattered across various healthcare facilities, medical centers, and insurance companies. To construct a comprehensive and accurate medical history, it is essential to amalgamate these disparate data fragments seamlessly. Blockchain technology serves as the keystone for this integration, providing a unified platform for storing all patient-related medical information—ranging from prescription histories and symptomatology to treatment modalities, facility utilization, financial transactions, and beyond.

Blockchain’s inherent characteristics ensure that the stored data remain current, verifiable, and impervious to tampering. This fortifies the ability of healthcare professionals to administer effective, prompt, and appropriate care. Moreover, the immutable, transparent, and secure nature of blockchain data empowers healthcare providers with a holistic view of a patient’s medical journey, thereby enhancing the precision of medical services rendered [15].

4.1.2. Making health information interoperable

Interoperability is the seamless exchange of information across diverse systems produced by various manufacturers. A multitude of Electronic Health Record (EHR) and Electronic Medical Record (EMR) products are founded on distinct clinical technologies, technical specifications, and functional capabilities, as noted in references [16]. These variances present obstacles in the creation and sharing of uniform data formats. In some instances, even EHR systems developed on identical platforms lack interoperability due to their customization to align with the unique needs and preferences of individual healthcare institutions. To bridge this gap, it is imperative that the transmission messages between EHR systems adhere to standardized coded data. The absence of such standardized data is a significant barrier, impeding the electronic sharing of data for patient care. This challenge can be surmounted through the adoption of a blockchain-based healthcare data management system. Within this system, all EHR/EMR data adheres to a uniform coding standard, thereby facilitating effortless access and utilization by any entity within the healthcare ecosystem [17].

4.1.3. Security of medical information

Over the past decade, a disturbing trend has emerged: numerous healthcare organisations have been targeted by cybersecurity attacks that could have been prevented [18]. Much of the healthcare sector still relies on manual, centralised systems to manage digital medical records. These systems are not only outdated, but also vulnerable to unauthorised changes with malicious intent. In addition, the centralised nature of these systems poses a risk of data loss during natural disasters, as they are susceptible to a single point of failure.

Introducing blockchain technology - the lighthouse of security in the digital age. The blockchain provides a robust solution to these security issues through its immutable ledger, which is underpinned by cryptographic principles and effectively eliminates the risks associated with the theft and mishandling of data. Furthermore, health data stored on a Blockchain is protected from the dangers of natural disasters or medical facilities collapsing. This is because there is no single point of failure, due to the decentralised storage of data across multiple nodes.

4.2. Challenges and Limitations in Healthcare Implementation

If used effectively, blockchain technology can provide a reliable approach to overcoming common limitations in healthcare applications, including issues related to privacy, confidentiality, reliability, sharing, interoperability, usability and timely updating of medical records. Despite these advantages, blockchain is not without its challenges. Integrating and applying it in healthcare has led to significant research hurdles, which need to be explored in depth. This section explores these challenges. A systematic classification is provided in the accompanying table3.

Table 3: Challenges of blockchain.

Overcoming Interoperability and Standardization Hurdles.

The seamless integration of healthcare applications remains a formidable challenge due to the lack of robust mechanisms for data collection, dissemination, and analysis. Traditional Electronic Health Record (EHR) systems are anchored in centralized databases and operate on isolated infrastructures. In stark contrast, blockchain technology offers a decentralized and cloud-based paradigm.

Embracing this innovative approach necessitates the creation of a dynamic EHR system, one that is adept at fostering collaboration and data exchange among the scientific and medical communities. Transitioning EHR data to a blockchain framework involves navigating a labyrinth of technological hurdles. Current healthcare databases, with their non-distributed nature, pose significant integration and scalability challenges [19].

4.3. Future Prospects and Ongoing Research

Through the above research, a synthesis of thematic concerns has emerged, poised to captivate the intellectual curiosity of future academicians. The forthcoming discourse aims to delve deeper into these revelations.

4.3.1. Adopting a comprehensive approach

The adoption of a holistic approach is paramount, not merely as a theoretical construct but as a pragmatic blueprint for circumventing system vulnerabilities and enhancing security. Such an approach ensures seamless interoperability, and fortifies the mechanisms of access management. A panoramic understanding of blockchain technology is indispensable for the inception of comprehensive, legally sound, and ethically robust electronic healthcare frameworks. These frameworks necessitate robust data governance and foolproof authentication protocols, laying the groundwork for a resilient digital health infrastructure [20].

Moreover, we champion the necessity of rigorous evaluation of blockchain-oriented e-healthcare ecosystems within diverse geopolitical and institutional milieus. This scrutiny is instrumental in forging bespoke healthcare solutions that resonate with the unique contours of local and global healthcare landscapes. It fosters synergistic collaborations with entities embedded in the healthcare matrix, including but not limited to, avant-garde medical research institutions.

4.3.2. Enhancing Architectural Efficacy

In the vanguard of blockchain’s evolution within healthcare, researchers are tasked with a pivotal mission: to refine and elevate the architecture of proposed or existing systems. The goal is to scale these systems adeptly, ensuring they rise to meet the anticipated surge in transactional demands as blockchain becomes increasingly woven into the fabric of healthcare operations.

This endeavor involves a meticulous focus on optimizing performance and efficiency. It is envisaged that by strategically mitigating network latency, augmenting throughput, and judiciously allocating resources, the architecture will not only withstand but thrive under the weight of burgeoning data exchanges [21].

4.3.3. Data Security and Legal Compliance

In the vanguard of future research, the safeguarding of data alongside the sanctity of patient privacy and the intricacies of legal compliance emerges as a paramount concern. The advent of blockchain technology offers a robust solution, with its immutable ledgers and smart contract verification systems providing a bulwark against breaches, ensuring adherence to stringent data and personal privacy mandates such as the Health Insurance Portability and Accountability Act (HIPAA) [22]. This innovative approach heralds a new era of security in the management of medical information, promising enhanced integrity and trust in healthcare data transactions.

4.3.4. Enhanced Integration with Cutting-Edge Technologies

The strategic deployment of blockchain technology within the healthcare sector stands to gain immensely from a seamless integration with core business processes, thereby amplifying its functionality. For instance, scholars could delve deeper into the fusion of edge computing, machine learning (ML), and artificial intelligence (AI) with blockchain-driven healthcare ecosystems. This synergy has the potential to revolutionize analytic models, paving the way for highly personalized patient care and diagnostics. Additionally, the research frontier could shift towards augmenting service quality by weaving in a denser network of IoT-based sensors. Such an integration promises to broaden service accessibility, fortify remote patient monitoring, and enhance emergency response services.

In pursuit of broadening the intellectual horizons in this domain, we advocate for two novel research trajectories. Firstly, an in-depth analysis of the ramifications of blockchain application in healthcare, particularly in nuanced yet analogous domains such as safeguarding patient’s digital rights, streamlining drug prescription management, and curbing prescription fraud, is imperative.

Lastly, an investigative lens should be turned towards the repercussions of blockchain adoption on healthcare valuation and supply chains. Such scholarly inquiry could illuminate the nuances of patient-centric interoperability challenges and potentially lay the groundwork for standardized protocols tailored for the adoption of blockchain systems in research methodologies.

5. Conclusion

This study delves into the integration of blockchain technology in healthcare systems, underscoring its potential to manage health data in a decentralized, secure manner, thereby enhancing transparency, accessibility, traceability, and trust. The immutable nature of blockchain presents a robust solution for secure, tamper-proof health data storage. The investigation covers the features and benefits of blockchain technology, demonstrating its capacity to overhaul healthcare data management. It identifies key opportunities within the healthcare sector, exemplified by case studies where blockchain has already improved various systems.

However, the research acknowledges significant challenges that currently hinder the widespread adoption of blockchain in healthcare. These challenges encompass the nascent stage of blockchain development, scalability issues, interoperability, the siloed nature of projects, and the complexity of integrating with existing legacy systems. In conclusion, blockchain technology holds transformative potential for the healthcare industry, offering significant improvements in operational efficiency, data security, workforce management, and cost-effectiveness. Overcoming the technical challenges mentioned is pivotal for its successful integration into healthcare.