Blockchain Application in Healthcare
Introduction
Blockchain is seen as a new technology which has the potential to transform the way information are shared. Blockchain is a distributed ledger which can track transactions and activities taking place throughout a network. The distinctive factor about blockchain is that once information is being added to the distributed ledger, the information cannot be altered by anyone. If someone wants to make a change on the block, it is required to make changes to the entire block after it (Pratap, 2018). Therefore, information stored on blockchain can be considered to be absolutely secure. Blockchain technology brings new possibilities in data sharing due to its unique structure. Sharing information through trust in decentralized environments is being considered a technological advancement which holds a lot of promise. In the Internet of Things era, more and more device communications are made possible but there are still challenges such as security of data yet to be overcome. Hence, blockchain has been considered as a potential solution to this. With the possible implementation of blockchain, data can be stored and shared securely.
Problem statement
Data Inconsistency
In terms of healthcare, patient’s data and medical records are spread across different hospitals, departments and even pharmacies. Therefore, important patient’s data is not accessible and shared among hospitals when needed. This can also cause friction due to data inconsistency and redundancy. The current healthcare system is not complete as smooth process management in terms of clinical data sharing has not been achieved.
Insecure data sharing
Data sharing, permission on who can access and store the data, securing patient and provider identities, and detection of fraudulent activities are some of the challenges which exist in healthcare till today. The misuse of data prevents healthcare organisation from delivering high quality patient care. Blockchain technology brings possibilities of solving these issues. With its distributed ledger and decentralised approach (Violino, 2018), it can allow interoperability of data in the healthcare sector by decentralising patient information.
2. Literature Review
2.1 Introduction to Blockchain
In 2008, Satoshi Nakamoto introduced two revolutionary concepts, one of it is the Bitcoin, a virtual digital currency that conserve its value without the backing from any centralised entity. (Nakamoto, 2008) The coin is supported securely by a decentralized peer-to-peer network of actors which make up an auditable and verifiable network. The second concept is blockchain. Blockchain is the technology which enables transaction to be verified by a group of unreliable actors. The blockchain can be referred openly, granting access to every transaction of the system performed since the very first transaction of the system, and any entity can verify the transaction anytime. The information are structured in chains of blocks by the blockchain protocol, where every block stores a set of transactions executed at a given time. Blocks are connected together by a reference to the previous block, thus creating a chain.
Network peers are required to provide functionalities such as routing, storage, mining and wallet services in order to support and operate with the blockchain (Antonopoulos, 2014). The routing function is essential in order to take part in P2P network, which includes transaction and block propagation. The function of storage is to keep a copy of the chain in the node. Wallet services allocate security keys, enabling users to perform transactions, such as making a transaction using Bitcoin or other cryptocurrencies. Lastly, the mining function is to create new blocks by solving and completing the proof of work. The mining process involves the nodes, known as miners, which perform the proof of work, and in return as reward, they receive newly generated bitcoins (or whichever cryptocurrencies they mine) and fees. The idea of proof of work plays a part in enabling trustless consensus in the blockchain network. The proof of work is composed of computationally intensive task which is required for blockchain generation. This work is complex to solve and easily verifiable at the same time once it is completed.
2.1.1 Smart Contract
Smart contract is another concept introduced by blockchain. Smart contract in general is computer protocol or program that enables a contract to be performed automatically once a set of predetermined conditions are met. For instance, smart contracts determine that an application logic will be performed whenever a transaction happens in the exchange of cryptocurrency. Other than cryptocurrency exchanges, smart contracts can also be used in other ways. Assets validation in a range of transactions which does not involve cash is an example which helps expand blockchain technology to other sectors. Ethereum (Buterin, 2013) is one of the first blockchains to implement smart contracts. Smart contracts have now been implemented in many other blockchains, one of which is Hyperledger (Androulaki, 2018), a blockchain designed for companies which enables components to be allocated according to user’s demand. Renowned companies such as IBM, JP Morgan, Intel and BBVA have implemented it.
2.2 Challenges
The idea of blockchain may sound simple, but its implementation actually comes with a number of challenges.
2.2.1 Storage capacity and scalability
The scalability and storage capacity of blockchain have been questionable. Blockchain is always growing at a rate of 1 MegaBytes per block every 10 minutes in Bitcoin, with copies stored among nodes in the network. Even though only full nodes store the full blockchain, storage requirements are still very significant. As the size increases, nodes will require more resources. Therefore, reducing the capacity scale of the system. Moreover, an oversized chain has negative result on the performance, as the synchronization time will increase for new users.
Transaction validation is an essential part of the distributed consensus protocol as in the blockchain network, nodes are expected to validate every transaction of each block. The amount of transaction in a block and the time between blocks regulate the computational power required and this affects the transaction confirmation times directly. Thus, consensus protocol has a direct impact on the scalability of blockchain networks (Diaz, Martin and Rubio, 2016).
2.2.2 Security weaknesses and threats
The 51% attack or also known as majority attack (Eyal and Sirer, 2014), is the most common attack on blockchain. Basically, if a blockchain member has the ability to control more than 51% of the mining power, this attack can occur. The person in this situation can control the consensus in the network. The sudden evolution of mining pools has contributed to the increase the probability of the occurrence of this attack, which could undermine the integrity of Bitcoin.
The double-spend attack happens when the same coin is spent twice. In Bitcoin transaction, a transaction is only considered to be confirmed after the block where the transaction is stored has a certain depth in the blockchain usually 5 or 6. It takes between 20 to 40 minutes on average (Bitcoin average transaction confirmation time, 2017). There is a sizeable variance in the confirmation time as it depends on many factors. In fast payment, trader cannot bear this wait. Hence, double-spend attacks can happen in this scenario.
Likewise, race attack can occur in these scenarios too. In order for this attack to happen, the user has to send a transaction directly to the merchant, who then accepts the transaction too fast. Then the user sends numerous conflicting transactions to the network, transferring the coins of the payments to himself. The second transaction is more likely to be confirmed, which cause the merchant to be cheated.
The famous Denial of Service (DoS) attacks, Man in the Middle or Sybil can also interrupt the operation of the network. Most peer to peer protocols and IoT infrastructures are susceptible to these attacks, since they depend on communication to a great extend. In the eclipse attack (Heilman et al., 2015), attackers can control a node’s connections, separating it from the rest of the network and changing the view of the network for this node.
2.2.3 Anonymity and data privacy
In blockchain (Diaz, Martin and Rubio, 2016), every transaction can be reviewed, inspect and tracked down from the very first transaction. Despite that, this transparency poses the direct effect on privacy. Even though, wallets and individuals do not relate, user anonymity seems to be undermined regardless of the mechanisms that Bitcoin provides, like pseudonymity and usage of multiple wallets. In this case, some work has been done to achieve stronger, more secured anonymity features and factors in Bitcoin. However, besides virtual currencies, many other applications based on blockchain technology require high level of privacy, especially those which deal with sensitive data.
There are attempts taken to approach the anonymity problem in Bitcoin. Some cryptocurrencies such as Zerocoin, now known as Zcash, (Miers et al., 2013) have introduced complete anonymous transactions, securing the identity of the sender, receiver, and its information. Similarly, Monero, another cryptocurrency, uses different approach to counter the problem. A ring of signatures is used to make transactions untraceable, causing it to be hard to track by any computer or person.
2.3 Smart Contracts
According to Reyna, Martin, Chen, Soler and Diaz (2018), one of the main features of smart contract is that its ability to execute contractual clauses by itself. Before blockchain, this was unachievable technologically. Smart contracts have contributed to the driving force of blockchain, this combination has created a second generation of blockchain, widely known as Blockchain 2.0. The code of the smart contract is stored on the blockchain. Every contract can be identified with a unique address. If users want to use it, they can send a transaction to the address. The correct execution of the contract will then be performed by the blockchain consensus protocol. The few advantages of smart contracts are cost reduction, precision, speed, transparency and efficiency. Even though Bitcoin offers a basic scripting language, it appears to be limited, which led to the introduction of new blockchain platforms with integrated smart contract functionality (Reyna et al., 2018).
One of the most notable smart contract blockchain is Ethereum. Ethereum is another blockchain which has built-in Turing complete programming language, which means it can be used to simulate any Turing machine, which enables smart contracts and decentralized applications. The contracts for ethereum are written in “Ethereum virtual machine code”, which is a low level, stack based bytecode language (Buterin, 2013).
The advantages of smart contracts come with a cost, as they are exposed a number of attacks. Entrusting contract execution to computers does bring problems, as it causes then to be exposed to technical issues such as bugs, hacking, communication viruses, to name a few. In contract coding, bugs are dangerous due to the unchangeable and fixed essence of the system. It is necessary for clients and providers to safely adopt the mechanisms of establishing and guaranteeing the correct operation of smart contracts. Research areas such as the formal validation of contract logic and its correctness expected to be refined and implemented in future (Luu et al., 2016).
In some cases, real-life contracts may have clauses that are unquantifiable. In such cases, there is still work to be done in order to structure the conditions of the contracts, to make them quantifiable and representable for execution by machines. Moreover, efforts to provide tools for users to specify and understand smart contracts are required (Frantz and Nowostawski, 2016).
2.4 IoT and blockchain integration
According to Diaz, Martin and Rubio (2016), the Internet of Things is revolutionizing and progressing manual processes to enable them, acquiring mass amount of data containing knowledge, which enables smart applications development such as the advancement of the quality and management of life of people through digitization of services in cities. In recent years, cloud computing has been instrumental in delivering the IoT with essential functionality to interpret and process information convert it to real-time actions and knowledge. This unparalleled advancement in the IoT has led to new possibilities and ways to access and share information. Centralized frameworks used in cloud computing have progressed the development of IoT. Despite that, in terms of data transparency, they are still unknown and there is no clear vision of how the information is used for network users (Diaz, Martin and Rubio, 2016).
Blockchain can enhance the IoT by implementing a trusted sharing service, enabling the information shared to be traceable and reliable. Data sources can be checked any time and data remains unchangeable, enhancing its security. The integration of IoT and blockchain can be a key revolution in cases where IoT information needs to be shared securely between users. For example, a complete food traceability in multiple food products is a vital point to maintain food safety. Food traceability includes the involvement of many entities: distribution, manufacturing, treatment, feeding, and more. A data leak in any part of the chain can cause issues and slow down the processes of the search for infection which can critically affect the lives of people and bring upon huge economic loss to companies, sectors and countries in the case of a foodborne outbreak (Buzby and Roberts, 2009). Food safety can be ensured with better control by enhancing data sharing between entities and minimizing search time for infection in a foodborne outbreak. Besides, blockchain can contribute in areas such as smart cars and smart cities. Sharing reliable data can lead to the incorporation of new entities in the ecosystems and improve the services and adoption. Thus, blockchain complements IoT with secure and reliable information. Blockchain is seen as a way to rectify privacy, scalability and reliability issues in the IoT model (Malviya, 2016).
2.4.1 Decentralization and scalability
The change from a centralized structure to a peer to peer distributed system will eliminate bottlenecks and central points of failure (Veena et al., 2015). It can also help prohibit big companies from controlling information processing and storage of the people. Other benefits such as the reduction of fault tolerance and improvement of system scalability can be achieved by reducing the IoT silos which contributes towards IoT scalability.
2.4.2 Identity
System participants and actors can have the ability to identify each devices used in the system if we use a common blockchain system. Data provided and stored in the system cannot be changed and actual data provided by a particular device can be uniquely identified. Moreover, blockchain is able to deliver trusted distributed authentication and authorisation of devices for IoT applications (Gan 2017). This leads to an advancement in IoT field and its members.
2.4.3 Autonomy
According to Blockchain of Things (2017), blockchain technology allows next generation application features, opening up opportunities and possibilities of smart autonomous assets and hardware development as a service. Devices will be able to interact with each other without the need of servers. IoT applications can take advantage from this functionality to achieve device agnosticism and decoupled applications (Filament, 2017).
2.4.4 Reliability
Information fo IoT can remain unchangeable and distributed over time in blockchain (Modum, 2017). Members of a system are able to verify the authenticity of the data and confirm that they have not been altered or interfered. Additionally, blockchain technology grants sensor data traceability and accountability. Reliability is the vital aspect of the blockchain to be integrated in IoT.
2.4.5 Security
Information and communication can be secured if they are stored as transactions of the blockchain (Prisco, 2016). Blockchain can use device message exchanges as transactions, authorized by smart contracts, in this way establishing communications between devices. Current secure standard-protocols implemented in the IoT can be optimized with the application of blockchain (Khan and Salah, 2017).
2.5 Blockchain IoT Interactions
One of the aspects to consider is regarding IoT interactions, such as communication between IoT infrastructure. In blockchain integration, it needs to be determined where the interactions will happen: Inside the IoT, a hybrid design approach involving both IoT and blockchain, or through blockchain. The introduction of fog computing (Aazam and Huh, 2014) revolutionizing the IoT with the inclusion of a new layer between cloud computing and IoT devices can also help in this integration. Below are the types of interactions described with their respective advantages and disadvantages.
2.5.1 IoT-IoT Approach
Since this approach can work offline, it is one of the fastest in terms of latency and security. IoT devices need to communicate with each other, and it usually involves discovery and routing mechanisms. In this approach, a part of IoT data is stored in blockchain while the IoT interactions occur without using the blockchain. This approach can be useful in situations with reliable IoT data where the IoT interactions are performed with low latency (Diaz, Martin and Rubio, 2016).
2.5.2 IoT-Blockchain
In this approach, all the interactions have to go through blockchain, which enables unchangeable record of interactions. It assures that all chosen interactions are trackable as the details can be queried and checked in the blockchain, and also increases autonomy of IoT devices. IoT applications which support trade and rent service can adopt this approach to offer their services. However, recording all interactions in blockchain will cause an increase of bandwidth and data, which is one of the major challenges for blockchain (Diaz, Martin and Rubio, 2016).
2.5.3 Hybrid Approach
Thirdly, the hybrid approach is where part of the interactions and data are performed and stored in the blockchain and the rest are shared directly between the IoT devices. The challenge of this approach is selecting which interactions to go through the blockchain and preparing the way to decide this in runtime. The best composition of this approach will be by integrating both technologies since it supports both the benefits of blockchain and real-time IoT interactions. This approach could involve cloud computing or even fog computing, as they complement the limitations of IoT and blockchain. For instance, lesser computationally-limited devices are involved in fog computing (Ethembedded, 2017; Raspnode, 2017).
2.6 Blockchain in Healthcare
Focusing on providing quality healthcare services to public means maintaining patient management at a high standard all the time. Nonetheless, the existence of federal rules and regulations worsen the process, making it more lengthy and tedious. Due to this, providing quality healthcare seems like an impossible task. Moreover, the dependency of middlemen in supply chain makes it worse.
In healthcare sector, patients’ data and information are not organized and may even be separated and scattered among different systems. Hence, important user data cannot be accessed when needed. For instance, when a patient is admitted to the nearest hospital due to emergency, the hospital does not have the patient’s data and past medical records if the patient has not been to the hospital before. The hospital is not able to access the patient’s data from other hospital due to current limitations in data sharing. This is a major problem in healthcare as there is no such system which stores and keep all patients data in place, which will smoothen the management process.
According to a study in the US, nearly half of the clinical trials in the country are not reported. Besides, almost 40% of hospital data records of patients are filled up with errors and misleading information. Moreover, it is estimated that data breaches in healthcare organizations cost about $380 per record, and this amount is expected to increase over time (Pratap, 2017). Many healthcare centres are still running on outdated system to keep local patient records.
With the help of blockchain technology, we may finally find a solution to this. This technology has the potential to improve patient care quality successfully, without increasing the healthcare costs significantly for patients. The issues that occur in multi level authentication can be solved through blockchain. Blockchain enables the creation and sharing of a single common database of health information where it can be easily accessible by doctor, patients, and pharmacists anytime no matter the medical system used. This provides high security and transparency of data, at the same time sparing doctors more this to spend on their patient, which in turn, improves patient care drastically. Besides, it will also provide better sharing of statistics for researchers, thus facilitating more clinical trials and treatment therapies for rare diseases.
There are two types of blockchain, namely the permissioned and permissionless blockchain which can be used as per the requirements and access permissions. For permissioned blockchains, as the name suggests enables real-time data to be shared between the participants of the network on a permissioned basis only. A permissioned blockchain is a private network where all the participants involved in the system have access to the network. It is built and used inside organizations and enterprises to exchange information and perform transactions securely. Once a transaction is processed through consensus, it will be treated as a permanent record and be added as a new block to the existing blockchain.
Permissionless blockchains provide access to anybody for creating an address of their own and begin interacting with the network. The internet is one of the famous examples of a permissionless system which allows anyone to create their own website. Similarly, in a permissionless blockchain, anyone on the network can interact with other users on the same network by registering their address on the network.
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