2. Chapter 2: Background and Literature Review
2.2. Blockchain-Based Applications
2.2.1. Blockchain for Performance Improvement
Xia et al. (2017) developed the blockchain-based system (MedShare) that facilitates the sharing of the patient’s medical data between cloud providers. This sharing is established while ensuring the consensus of the patients and the actual behavior for each entity is monitored to ensure that no unauthorized actions are performed by any party. This system is divided into the following layers: user layer, data query layer, data structuring layer, and database infrastructure layer. User layer defines and classifies all of the users that are allowed to access the data for research tasks. The data query layer defines how the users can access the data. In such system, data is expected to be stored in different databases and the data structure layer handles how and who can access the data and also record all of the initiated requests to the blockchain. The database infrastructure layer handles the passing of the datasets between the peers. This system targets the main two features which are behind the existence of the blockchain technology, namely traceability and security.
However, the regulator entity should be owned and handled by trusted authority since it has access to very critical information.
25 Likewise, Jiang et al. (2018) built a blockchain solution termed BlockHIE. This solution consisted of three components: blockchain network, medical institutes, and patients who are willing to store their data on the system. In this solution, blockchain is used to store the patient users and manage the information sharing between the medical institutes. Medical institutes use the stored information during the diagnosis and treatment of the patients. Beside the traditional way of uploading medical reports to the systems, the system gathers the medical information through the use of IoT devices such as smart watches and smart thermometers. Once the hospital creates a medical record for a patient, three copies of this record are generated. The first copy is sent to the patient and the second copy is kept at the hospital. These two copies are totally identical. The third copy, which is kept in the blockchain, represents a summary of the report information and it acts as a proof-of-existence for the other two copies. This is due to the limited storage capabilities on the blockchain. In addition, uploading relatively large amount of data to the blockchain requires a huge throughput. The provided system ensures the traceability of the initialized report in emergency related situations. However, accessing the actual historical tests in timely manner is more important than locating their existence. Similarly, Turkanović, Hölbl and Košič (2018) proposed Blockchain-based solution to address and manage the process of initiating student’s certificates and attestation.
To reduce the amount of computation used by the consensus protocol, Alzahrani and Bulusu (2018) suggested a random validator selection mechanism. In this mechanism, nodes are assigned randomly to validate each other. In addition, once a block is required to be validated, only log𝑛
3 of the node will perform the mining process. These nodes are selected at random with the objective of distributing and producing the energy consumption
26 related to the consensus activities. This system is designed mainly for public blockchain and this highlights the importance of the author provided consensus mechanism. However, such system architecture can be easily moved to private blockchain and that will reduce the pressure on the consensus mechanism.
Chen et al. (2017) presented a Blockchain-based framework for information sharing and quality control. This framework consists of four layers, namely IoT layer, data layer, contract layer and business layer. All of these layers work together to support and provide the required information to help achieving the business goals. The IoT layer consists of sensor and RFID technology that can be used to monitor and capture the required measure from the business perspective. The data layer is the blockchain layer and all of the capture information in the sensor layer is added to the blockchain layer to support the other two layers decisions. The contract layer represents the logic of the system and it is implemented through the use of the smart contract. This layer supports the business layer by providing the required inputs. The business layer represents the global objective of the network and it uses the provided information by the contract layer to make the final business decision.
This architecture seems to be self-contained and logical. However, detailed investigation about the objectives and drawback of adopting such architecture must be performed by the authors.
Lu and Xu (2017) developed origin-chain, a blockchain-based solution to provide tamper-proof data traceability and regulation validation management system. In this system, the product supplier contacts the traceability provider in order to arrange for the traceability contract. This contract represents the type of validation and must be performed by the service provider. The business flow in this scenario consists of three types of entities,
27 namely suppliers, labs and traceability service provider. The actual process of tracing is performed through the use of the factory contract. This contract issues two types of services: registry contract and service contract. Registry contract contains the legal information for the agreement between the service provider and the supplier. On the other hand, service contract is used to add or remove conditions to the original traceability agreement. The lab periodically uploads the test results based on the type of the agreement at the traced product.
Li and Wang (2018) proposed a blockchain-based system that ensures the privacy of the transactions in financial platforms. The main parties in this system are: the verifiers, the participants and the supervisors. Any participant can play the role of the verifier to validate the transaction on the blockchain. Participants refer to the customer and service provider where the supervisor represents the third-party authority, which ensures the satisfaction of the financial constraints. In this system, the supervisor makes sure that the participating entities in the trade are behaving within the legitimate boundaries. Once two or more participants start conversation action to perform a specific deal, this supervisor monitors the information exchange and interfere whenever necessary. Again, this system targets the security and traceability of information through the use of blockchain technology. However, the scalability factor of this system should be investigated.