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The top priority of today’s healthcare system is delivering medicine directly from the manufacturer to end-user. The pharmaceutical supply chain involves some level of commingling of a collection of stakeholders such as distributors, manufacturers, wholesalers, and customers. The biggest challenge associated with this supply chain is temperature monitoring as well as counterfeit drug prevention. Many drugs and vaccines remain viable within a specific range of temperatures. If exposed beyond this temperature range, the medicine no longer works as intended. In this paper, an Internet of Things (IoT) sensor-based blockchain framework is proposed that tracks and traces drugs as they pass slowly through the entire supply chain. On the one hand, these new technologies of blockchain and IoT sensors play an essential role in supply chain management. On the other hand, they also pose new challenges of security for resource-constrained IoT devices and blockchain scalability issues to handle this IoT sensor-based information. In this paper, our primary focus is on improving classic blockchain systems to make it suitable for IoT based supply chain management, and as a secondary focus, applying these new promising technologies to enable a viable smart healthcare ecosystem through a drug supply chain.
Keywords: scalability, blockchain, sensors, IoT, security, distributed network, supply chain, temperature monitoring
Transportation of pharmaceuticals (drugs, vaccines, supplies) from manufacturer to patient follows a stringent supply chain. The critical challenge of this supply chain management is safe transportation. The healthcare industry has an increasing number of counterfeit drugs on the market, and one in ten medical products are falsified in most developing countries. These medicines contain an incorrect ingredient or no active ingredient. Take for example, the current global pandemic of COVID-19. A British Broadcasting Channel (BBC) News investigation found fake drugs for sale in Africa, where counterfeiters are exploiting growing gaps in the market. The World Health Organization (WHO) said taking these drugs could have “serious side effects” [1]. The other key challenge is many pharmaceuticals are supposed to remain viable or effective only within a certain range of temperatures. If the temperature becomes too hot or cold, these medicines become ineffective, thus do not work as they are intended to. Being able to verify the temperature conditions and authenticity of medicines allow medical professional or patients to discard medicines that are no longer active or effective. When proper medication is found, the supply chain of that medication will need to be monitored closely both for the authenticity of medication as well as if any of the useful ingredients are temperature sensitive [2]. Patients, pharmacies, hospitals all rely on the medicinal supply chain and logistics companies that deliver heat-sensitive medicines, such as vaccines or insulin. During the transportation of these medicines over thousands of kilometres, a smart transportation box is required that maintains the temperature and records all changes into a pre-programmed sensor. The system of transporting and storing the vaccine at a certain temperature from manufacturer to the point of consumption is called Cold Chain. The essential elements of a cold chain are: equipment for vaccine transport and storage and equipment to monitor the temperature of the vaccine. Since trust among all participants and stakeholders in the supply chain or cold chain is required, incorporating any sort of blockchain technology should be considered a strong solution. Blockchain technology can store all sensor data and cannot be manipulated. Using blockchain, therefore, builds trust among a smart digital health ecosystem. All the important information about how drugs are entered and moved through the supply chain is available to everyone who is connected to the blockchain system. The sensor (see Figure 1 ) can collect the data—for example, the temperature inside the package while drugs are in transit from one place to another [3,4,5,6,7,8].
Temperature tracker sensor.
The QR code stores all necessary information regarding sensor, temperature range, temperature threshold, owner information, etc. The QR code has two blank information cells (low temperature and high temperature). During transit, if the temperature changes beyond a given threshold for that particular drug, then it stores that temperature in the QR code blank cells. The sensor also shows a red light if the temperature has ever gone beyond the threshold and blinks green if the temperature has remained under the threshold. Once delivery is completed, sensor data can be transferred to the cloud using QR code Readers (see Figure 2 ) and the hash of the QR code is stored in a blockchain.
Quick response (QR) code reader.
Nowadays, handheld smartphone devices are predominantly used as a QR code scanner and reader. However, the security of these sensor devices is another issue. Therefore, we need some digital signature scheme to confirm that the data is not modified by the attacker. The other issue with sensor networks is time synchronization of all sensors. Any form of sensor data fusion requires a synchronized clock. The problem of time synchronization in sensor networks was briefly described in the article [9]. To address the problem of time synchronization in sensor networks, the Berkeley algorithm [10] is one of the famous algorithms developed by Gusella and Zatti at the University of California, Berkeley.
One of the well-known drawbacks of blockchain technology is the scalability of the network. Scalability is defined as one of the most vital problems in blockchain technology and has been a prime focus in the blockchain community since its onset. The integration of IoT devices to the blockchain is challenging. IoT devices generate a large amount of data, and blockchains cannot handle them due to their low throughput or transaction execution rate. There are quite a few consensus algorithms available for blockchain that support high throughput; however, they require extremely high-performance for the network. In the proposed model, we used Raft consensus algorithms that provide high throughput, but Raft is only suitable for a small number of participants in the network. Increasing the nodes in the network decreases the efficiency and throughput of Raft due to low network scalability. The Raft algorithm expects very fast data transmission to provide high throughput. Therefore, we increase network performance by using the bloXroute [11] server concept. These bloXroute servers propagate the blocks very fast in the network. However, the bloXroute server propagates only encrypted blocks that prevent it from stopping the block propagation based on its content, and therefore node discrimination is not possible by servers. Please note that bloXroute is not a blockchain itself but it is a highly scalable distributed network only. Collecting encrypted data from resource-constrained devices, for example, the QR code scanner, is also a major issue. Currently, many applications like sensor networks or RFID are implemented on devices with very limited capabilities, and they require lightweight encryption. Many well-known standard algorithms, for example, AES, do not stand up to the basic requirements of constrained devices. This includes the need for minimal cost hardware implementation, minimal power usage, and minimal latency. In response to these problems, lightweight cryptographic primitives have been proposed in this model. These algorithms are usually smaller and faster for IoT based software implementation. Another major issue in need of addressing is the security of sensor devices with lightweight digital signature schemes. To know if the sensor data is coming from a reliable source, a digital signature can play an important role.
The rest of this paper is organized as follows. In Section 2, we summarize the recent related works connected to our study here. Next, our system is summarized in Section 3. We discuss several cryptographic techniques in Section 3.3. Our main evaluations occur in Section 4 and Section 5, where we give a performance evaluation and security analysis, respectively. The paper ends with some future directions and concluding remarks in Section 6.
Malik et al. [12] proposed a three-layered framework for trust management known as TrustChain. TrustChain is shown as a blockchain technology-based application for supply chain, which is used to navigate trust issues that are linked to commodity quality. TrustChain makes use of a consortium blockchain that is used to monitor interactions with all participants on the supply chain participants. It also in dynamic fashion assigns both a reputation score and trust score solely based on interactions within the supply chain. Their intricate framework is also vital to give a reputation model that is both the asset and agent-based. The authors provide an in-depth security analysis focussing on threats to the reputation system. We can summarize the new notions of Trustchain stems as:
Based on several observations of supply chain events, the proposed model evaluates the product quality and entities trustworthiness.
Assigns the reputation scores to each participant and also product-specific score to the same participant in the supply chain.
It uses smart contracts for automated, secure, efficient and transparent calculation of the score.The blockchain overhead in terms of throughput and latency is minimal compared to other supply chain blockchain models.
Caro et al. [13] presented a blockchain-based Agriculture-Food supply chain, named AgriBlockIoT. The proposed model integrates IoT devices with the supply chain and processes all the data in the supply chain with the help of IoT. AgriBlockIoT also integrates blockchain along with IoT to create auditable, transparent and immutable records used for the traceability of supply chain management. Authors used two different blockchains, Hyperledger Sawtooth and Ethereum. The proposed framework also developed a use case named as “from-farm-to-fork” and presented the pros and cons of their system by comparing and evaluating the latency, network usage and CPU performance.
Jamil et al. [14] proposed a blockchain-based framework to handle the pharmaceutical drugs supply chain. In the proposed, framework, a Hyperledger Fabric blockchain is used that is based on proof-of-concept consensus. The framework describes the implementation, design and performance of Hyperledger Fabric blockchain for smart hospitals. The blockchain system enables the pharmacists, nurses, patients and doctors to manage the healthcare ecosystem along with medical records. A smart contract is developed with solidity programming code and is also used along with a permission blockchain system. By utilizing this blockchain and smart contract-based system, the framework mitigates the issue of counterfeit drugs. However, they have not analyzed the supply chain management of biopharmaceutical drugs (for example, vaccines) that have special temperature and weather requirements, which is one of the most important problems nowadays.
Kapoor et al. [15] provided a comprehensive overview of the Pharmaceutical Supply Chain. They analyze the benefits of the supply chain and discussed strategic issues and challenges in the pharmaceutical supply chain.
Bishara [16] developed a framework for cold chain management of pharmaceutical drugs to manage the issues of risk assessment factors, quality management, distribution practices, and temperature monitoring. Developing a humidity and temperature monitoring system is essential to maintain the quality of biopharmaceutical drugs. Through our literature search, our efforts to find pertinent literature that dealt with the work we are proposing in this paper was limited.
When focussing on throughput, Gorenflo et al. introduced FastFabric, which is able to increase the throughput in Hyperledger significantly [17]. Furthermore, Stathakopoulou et al. also tackle increasing the low throughput in classic blockchain with work on Mir-BFT [18].
In our in-depth literature search, the work presented in this paper is the first look at such a framework in relation to drug transport protocols. The novelty of the work and contributions comes through the designed framework and use of secure components that, when used in tandem, provide a secure system for temperature-controlled pharmaceuticals to be transported through the supply chain.
A supply chain is an interconnected network of nodes pertaining to organizations, individuals, technologies, resources involved in the manufacture and sale of the products (see Figure 3 ). A supply chain starts from the supplier who delivers the raw materials and ends with the end-user customer, for example, hospitals, patients, pharmacy shops. The supply chain takes care of movement and storage of produced medicines from source to the destination. A pharmaceutical drug supply chain system has the following important elements:
Manufacturers: The manufacturer receives orders from wholesalers or distributors and ships the finally produced pharmaceutical drugs in large quantities to distributor warehouses.
Wholesalers: The wholesaler propagates the process and distributes pharmaceutical drugs to pharmacies and hospitals. This saves time and effort of the manufacturer from the distribution of drugs.
Pharmacies: Pharmacies and hospitals purchase the pharmaceutical drugs from wholesalers. The drugs received by pharmacies and hospitals are given or sold to end-users or patients.
