The last decade has experienced a vast interest in Blockchain-based cryptocurrencies with a specific focus on the applications of this technology. However, slow confirmation times of transactions and unforeseeable high fees hamper their wide adoption for micro-payments. The idea of establishing payment channel networks is one of the many proposed solutions to address this scalability issue where nodes, by utilizing smart contracting, establish payment channels between each other and perform off-chain transactions. However, due to the way these channels are created, both sides have a certain one-way capacity for making transactions. Consequently, if one sides exceeds this one-way capacity, the channel becomes useless in that particular direction, which causes failures of payments and eventually creates an imbalance in the overall network. To keep the payment channel network sustainable, in this paper, we aim to increase the overall success rate of payments by effectively exploiting the fact that end-users are usually connected to the network at multiple points (i.e., gateways) any of which can be used to initiate the payment. We propose an efficient method for selection of the gateway for a user by considering the gateway's inbound and outbound payment traffic ratio. We then augment this proposed method with split payment capability to further increase success rate especially for large transactions. The evaluation of the proposed method shows that compared to greedy and maxflow-based approaches, we can achieve much higher success rates, which are further improved with split payments.
Erikson J. de Aguiar, Bruno S. Faiçal, Bhaskar Krishnamachari, Jó Ueyama
Blockchain technology has been gaining visibility owing to its ability to enhance the security, reliability, and robustness of distributed systems. Several areas have benefited from research based on this technology, such as finance, remote sensing, data analysis, and healthcare. Data immutability, privacy, transparency, decentralization, and distributed ledgers are the main features that make blockchain an attractive technology. However, healthcare records that contain confidential patient data make this system very complicated because there is a risk of a privacy breach. This study aims to address research into the applications of the blockchain healthcare area. It sets out by discussing the management of medical information, as well as the sharing of medical records, image sharing, and log management. We also discuss papers that intersect with other areas, such as the Internet of Things, the management of information, tracking of drugs along their supply chain, and aspects of security and privacy. As we are aware that there are other surveys of blockchain in healthcare, we analyze and compare both the positive and negative aspects of their papers. Finally, we seek to examine the concepts of blockchain in the medical area, by assessing their benefits and drawbacks and thus giving guidance to other researchers in the area. Additionally, we summarize the methods used in healthcare per application area and show their pros and cons.
Shaoyong Guo, Yao Dai, Song Guo, Xuesong Qiu · 5 authors
Blockchain technology is developing rapidly and has been applied in various aspects, among which there are broad prospects in Internet of Things (IoT). However, IoT mobile devices are restricted in communication and computation due to mobility and portability, so that they can't afford the high computing cost for blockchain mining process. To solve it, the free resources displayed on non-mining-devices and edge cloud are selected to construct collaborative mining network(CMN) to execute mining tasks for mobile blockchain. Miners can offload their mining tasks to non-mining-devices within a CMN or the edge cloud when there are insufficient resources. Considering competition for resource of non-mining-devices, resource allocation problem in a CMN is formulated as a double auction game, among which Bayes-Nash Equilibrium (BNE) is analyzed to figure out the optimal auction price. When offloading to edge cloud, Stackelberg game is adopted to model interactions between edge cloud operator and different CMNs to obtain the optimal resource price and devices' resource demands. The mechanism realizes improving the mining utility in mining networks while ensuring the maximum profit of edge cloud operator. Finally, profits of mining networks are compared with an existing mode which only considers offloading to edge cloud. Under the proposed mechanism, mining networks obtain 6.86% more profits on average.
In recent years, many researchers have focused on developing a feasible solution for storing and exchanging medical images in the field of health care. Current practices are deployed on cloud-based centralized data centers, which increase maintenance costs, require massive storage space, and raise privacy concerns about sharing information over a network. Therefore, it is important to design a framework to enable sharing and storing of big medical data efficiently within a trustless environment. In the present paper, we propose a novel proof-of-concept design for a distributed patient-centric image management (PCIM) system that is aimed to ensure safety and control of patient private data without using a centralized infrastructure. In this system, we employed an emerging Ethereum blockchain and a distributed file system technology called Inter-Planetary File System (IPFS). Then, we implemented an Ethereum smart contract called the patient-centric access control protocol to enable a distributed and trustworthy access control policy. IPFS provides the means for decentralized storage of medical images with global accessibility. We describe how the PCIM system architecture facilitates the distributed and secured patient-centric data access across multiple entities such as hospitals, patients, and image requestors. Finally, we deployed a smart contract prototype on an Ethereum testnet blockchain and evaluated the proposed framework within the Windows environment. The evaluation results demonstrated that the proposed scheme is efficient and feasible.
Recent advancement of Bitcoin revolution has propelled unlimited opportunities for futuristic digital ecosystem design. Transactions belonging to Bitcoin are being fully supported, realized, and disseminated by a set of innovative hot and cold wallet technologies within the blockchain framework. While deploying smart applications under the niche of Internet of Things (IoT) plethora, such Bitcoin transactions aroused the issue of unsupported resource-constrained tool sets and demanded for a novel architecture. To cater this challenge, this article proposes a novel Bitcoin lightweight IoT node-based system model while incorporating the improved simplified payment verification (SPV) process for e-healthcare application. This article, first formulates necessary models of background arts utilized in the work that include inhomogeneous Poisson point process, block header structure formulation, depth and height relationship, bloom filter mechanism, pay-to-public key hash (P2PKH) base stack process, and transaction management. Second, developed models are deployed through several key algorithms and associated procedures. Finally, analysis and discussions are made that encompass the block confirmation time, appropriateness of the byzantine fault tolerance, smart contract policy, and SPV response in the proposed scenario.
Younghun Lee, Shailendra Rathore, Jin Ho Park, Jong Hyuk Park · 6 authors
Abstract With the advancement of Information and Communication Technology (ICT) and the proliferation of sensor technologies, the Internet of Things (IoT) is now being widely used in smart home for the purposes of efficient resource management and pervasive sensing. In smart homes, various IoT devices are connected to each other, and these connections are centered on gateways. The role of gateways in the smart homes is significant, however, its centralized structure presents multiple security vulnerabilities such as integrity, certification, and availability. To address these security vulnerabilities, in this paper, we propose a blockchain-based smart home gateway network that counters possible attacks on the gateway of smart homes. The network consists of three layers including device, gateway, and cloud layers. The blockchain technology is employed at the gateway layer wherein data is stored and exchanged in the form blocks of blockchain to support decentralization and overcome the problem from traditional centralized architecture. The blockchain ensures the integrity of the data inside and outside of the smart home and provides availability through authentication and efficient communication between network members. We implemented the proposed network on the Ethereum blockchain technology and evaluated in terms of standard security measures including security response time and accuracy. The evaluation results demonstrate that the proposed security solutions outperforms over the existing solutions.
Muhammad Salek Ali, Massimo Vecchio, Guntur Dharma Putra, Salil S. Kanhere · 5 authors
Within the Internet of Things (IoT) and blockchain research, there is a growing interest in decentralizing health monitoring systems, to provide improved privacy to patients, without relying on trusted third parties for handling patients' sensitive health data. With public blockchain deployments being severely limited in their scalability, and inherently having latency in transaction processing, there is room for researching and developing new techniques to leverage the security features of blockchains within healthcare applications. This paper presents a solution for patients to share their biomedical data with their doctors without their data being handled by trusted third party entities. The solution is built on the Ethereum blockchain as a medium for negotiating and record-keeping, along with Tor for delivering data from patients to doctors. To highlight the applicability of the solution in various health monitoring scenarios, we have considered three use-cases, namely cardiac monitoring, sleep apnoea testing, and EEG following epileptic seizures. Following the discussion about the use cases, the paper outlines a security analysis performed on the proposed solution, based on multiple attack scenarios. Finally, the paper presents and discusses a performance evaluation in terms of data delivery time in comparison to existing centralized and decentralized solutions.
Onno W. Purbo, Sriyanto Sriyanto, Suhendro Suhendro, RZ Abdul Aziz · 5 authors
In this paper, we report the benchmarking results of Hyperledger, a Distributed Ledger, which is the derivation Blockchain Technology. Method to evaluate Hyperledger in a limited infrastructure is developed. Themeasured infrastructure consists of 8 nodes with a load of up to 20000 transactions/second. Hyperledger consistently runs all evaluation, namely, for 20,000 transactions, the run time 74.30s, latency 73.40ms latency, and 257 tps. The benchmarking of Hyperledger shows better than a database system in a high workload scenario. We found that the maximum size data volume in one transaction on the Hyperledger network is around ten (10) times of MySQL. Also, the time spent on processing a single transaction in the blockchain network is 80-200 times faster than MySQL. This initial analysis can provide an overview for practitioners in making decisions about the adoption of blockchain technology in their IT systems.
Recently, we have seen increasing popularity of using the blockchain technology to secure sensing data generated by traditional wireless sensor networks and Internet of Things (IoT). One of the biggest obstacles for integrating the IoT and blockchain technologies is the limited throughput of the current distributed ledgers. In this paper, we propose a novel method for hierarchical processing and logging of potentially large amount of sensing data with the blockchain technology, which could drastically address the issue of limited throughput in blockchains. Depending on the scale of the sensing need, two or more levels of processing and logging could be involved, where only the highest level of summative sensor data are placed on the blockchain or a secure distributed ledger. By establishing a strong linkage between different level of data, all lower-level and raw data are also made immutable once the highest level of summative data are placed on the blockchain.
Blockchain technology offers an intelligent amalgamation of distributed ledger, Peer-to-Peer (P2P), cryptography, and smart contracts to enable trustworthy applications without any third parties. Existing blockchain systems have successfully either resolved the scalability issue by advancing the distributed consensus protocols from the control plane, or complemented the security issue by updating the block structure and encryption algorithms from the data plane. Yet, we argue that the underlying P2P network plane remains as an important but unaddressed barrier for accelerating the overall blockchain system performance, which can be discussed from how fast and reliable the network is. In order to improve the blockchain network performance about enabling fast and reliable broadcast, we establish a trust-enhanced blockchain P2P topology which takes transmission rate and transmission reliability into consideration. Transmission rate reflects blockchain network speed to disseminate transactions and blocks, and transmission reliability reveals whether transmission rate changes drastically on unreliable network connection. This paper presents BlockP2P-EP, a novel trust-enhanced blockchain topology to accelerate transmission rate and meanwhile retain transmission reliability. BlockP2P-EP first operates the geographical proximity sensing clustering, which leverages K-Means algorithm for gathering proximity peer nodes into clusters. It follows by the hierarchical topological structure that ensures strong connectivity and small diameter based on node attribute classification. Then we propose establishing trust-enhanced network topology. On top of the trust-enhanced blockchain topology, BlockP2P-EP conducts the parallel spanning tree broadcast algorithm to enable fast data broadcast among nodes both intra- and inter- clusters. Finally, we adopt an effective node inactivation detection method to reduce network load. To verify the validity of BlockP2P-EP protocol, we carefully design and implement a blockchain network simulator. Evaluation results show that BlockP2P-EP can exhibit promising network performance in terms of transmission rate and transmission reliability compared to Bitcoin and Ethereum.
As one of the key technologies of distributed ledgers, blockchain solves the trust problem in open network without relying on any trusted third party. Its decentralized feature has a broad application prospect, but still faces scalability problem. Currently, blockchain scalability bottleneck is mainly in three aspects: performance inefficiency, high confirmation delay, and function extension. For example, Bitcoin can only deal with 7 transactions per second averagely. Obviously, it cannot meet the requirement of current digital payment scenarios, nor can it be carried in other applications such as distributed storage and credit service. What's more, different blockchain systems carry different business and requirements, so scalability is the core issue of the current development of blockchain. This paper introduces the blockchain scalability related technologies from the aspects of improving efficiency and extending functionality of blockchain system, respectively. We summarize four mainstream solutions to improve the performance of blockchain system, including Sharding mechanism, directed acyclic graph based (DAG-based), off-chain payment network and cross-chain technology. In the end, we give some suggestions for further research in blockchain scalability.
Bo Zhao, Yifan Liu, Xiang Li, Jiayue Li · 5 authors
The data layer devices in the Software Defined Network (SDN) play an important role in packet forwarding. However, whether the forwarding task can be efficiently completed by the node has not attracted enough attention. A method called TrustBlock is proposed in this paper, which introduces trust as a security attribute in SDN routing planning. Besides, in order to enhance the integrity and controllability of trust evaluation, the double-layer blockchain architecture is established. In the first layer, the behavior data of the node is recorded, and then the trust calculation is performed in the second layer. In the evaluation model, nodes' trust is calculated from three aspects: direct trust, indirect trust and historical trust. Firstly, from the perspective of security, blockchain is used to achieve identity authentication of nodes, after that, from the perspective of reliability, the forwarding status is used to calculate the trust value. Secondly, consensus algorithm is used to filter malicious recommendation trust value and prevent colluding attacks. Finally, the adaptive historical trust weight is designed to prevent the periodic attack. In this paper, the entropy method is used to determine the weight of each evaluation attribute, which can avoid the problem that the subjective judgment method is not adaptable to the weight setting. Simulation results show that the detection rate of the TrustBlock is up to 98.89%, which means this model can effectively identify the abnormal nodes in SDN. Moreover, it is attractive in terms of integrity and controllability.
Different from the traditional healthcare field, Medical Cyber Physical Systems (MCPS) rely more on wireless wearable devices and medical applications to provide better medical services. The secure storage and sharing of medical data are facing great challenges. Blockchain technology with decentralization, security, credibility and tamper-proof is an effective way to solve this problem. However, capacity limitation is one of the main reasons affecting the improvement of blockchain performance. Certificateless aggregation signature schemes can greatly tackle the difficulty of blockchain expansion. In this paper, we describe a two-layer system model in which medical records are stored off-blockchain and shared on-blockchain. Furthermore, a multi-trapdoor hash function is proposed. Based on the proposed multi-trapdoor hash function, we present a certificateless aggregate signature scheme for blockchain-based MCPS. The purpose is to realize the authentication of related medical staffs, medical equipment, and medical apps, ensure the integrity of medical records, and support the secure storage and sharing of medical information. The proposed scheme is highly computationally efficient because it does not use bilinear maps and exponential operations. Many certificateless aggregate signature schemes without bilinear maps in Internet of things (IoT) have been proposed in recent years, but they are not applied to the medical field, and they do not consider the security requirements of medical data. The proposed scheme in this paper has high computing and storage efficiency, while meeting the security requirements in MCPS.
Recently, software-defined Industrial Internet of Things (SDIIoT), the integration of software-defined networking (SDN) and Industrial Internet of Things (IIoT), has emerged. It is perceived as an effective way to manage IIoT dynamically. Aiming to improve the scalability and flexibility of SDIIoT, multi-SDN has been applied to form a physically distributed control plane to handle a large amount of data generated by industrial devices. However, as the core of multi-SDN, reaching consensus among multiple SDN controllers is a thorny issue. To meet the required design principle, this article proposes a blockchain-enabled distributed SDIIoT to synchronize local views between distinct SDN controllers and finally reach the consensus of the global view. On the other hand, both the cryptographic operations of blockchain and the noncryptographic tasks have access to the same computational resource pool of mobile edge cloud (MEC). In order to optimize the system energy efficiency, we adaptively allocate computational resources and the batch size of the block by jointly considering the trust features of SDN controllers and the resource requirements of noncryptographic operations. To implement the truly distributed manner of blockchain, we describe our problem as a partially observable Markov decision process (POMDP) and propose a novel deep reinforcement learning (DRL) approach to solve it. In the simulation results, we compare three different protocols of blockchain and show the effectiveness of our scheme in each of them.
Subhi Alrubei, Edward A. Ball, Jonathan Rigelsford, Callum. A Willis
The Internet of Things (IoT) is increasingly being utilized, by both businesses and individuals, for many applications. This utilization means increases in the smart devices that are connected to the Internet of Things, which will significantly increase the challenges related to devices' interconnectivity and management, data and user privacy, and network, data, and device security. At the same time, blockchain approaches provide a decentralized, immutable, and peer-to-peer ledger technology that could be the right answer to these challenges. Significant challenges, however, accompany the integration of blockchain into the Internet of Things, since IoT smart devices may suffer from resource and power constraints and blockchain is associated with scalability and delay issues. In this paper, a practical incorporation of blockchain into the Internet of Things is demonstrated using Ethereum Proof of Authority (PoA). This provides performance analyses, which include measurement of the transaction arrival time, the system end-to-end latency for different network implementations over cellular and Wi-Fi, and the average power consumption. This includes the study of the effect of network bandwidth on the stability and synchronization of all nodes on the blockchain network.
Purpose A blockchain is a shared distributed ledger technology that stores the information of every transaction in the network. The blockchain has emerged with a huge diversity of applications not only in the economic but in the non-economical domain as well. Blockchain technology promises to provide a wide range of solutions to the problems faced during implementation of smart cities. It has the potential to build smart contracts more secure, thus eliminating the need for centralized authority. Design/methodology/approach This paper presents a proof-of-concept for a use case that uses an Ethereum platform to build a blockchain network to buy, sell or rent a property. Findings The findings of this study provide an opportunity to create novel decentralized scalable solutions to develop smart cities by enabling paperless transactions. There are enormous opportunities in this distributed ledger technology which will bring a revolutionary change in upcoming years. Originality/value The concept of blockchain along with smart contracts can be used as a promising technology for sharing services which is a common requirement in smart cities. All the blockchain transactions are stored in decentralized shared database. The transaction recorded in decentralized system is immutable, it cannot be altered and hence chance of forgery is negligible.
Ethereum, the largest blockchain for running smart contracts, charges the people who send transactions to deploy or invoke smart contracts for thwarting resource abuse. The amount of transaction fee depends on the size of that contract and the operations executed by that contract. Consequently, smart contracts with inefficient code will waste money. In this article, we propose and develop the first tool, namedGasChecker, for automatically identifying gas-inefficient code in smart contracts, and conduct the first empirical study on the prevalence of gas-inefficient code in the deployed smart contracts. More precisely, we first summarize ten gas-inefficient programming patterns and propose a new approach based on symbolic execution (SE) to detect them in the bytecode of smart contracts. To make our approach scalable to analyze millions of smart contracts, we parallelize SE by tailoring it to the MapReduce programming model, and propose a new feedback-based load balancing strategy to effectively utilize cloud resources. Extensive experiments show thatGasCheckerscales well with the increase of workers. The empirical study demonstrates that lots of real smart contracts contain various inefficient code. Manual investigation demonstrates that only 2.5 percent of discovered gas-inefficient instances are false positives.
The advent of Internet of Things (IoT) brought innovation along with unprecedented benefits of convenience and efficacy in many operations that were otherwise very cumbersome. This innovation explosion has surfaced a new dimension of vulnerability and physical threat to the data integrity of IoT networks. Implementing conventional cryptographic algorithms on IoT devices is not future-proof as these devices are constrained in terms of computational power, performance, and memory. In this paper, we are proposing a novel framework, a unique model that integrates IoT networks with a blockchain to address potential privacy and security threats for data integrity. Smart contracts are instrumental in this integration process and they are used to handle device authentication, authorization and access-control, and data management. We further share a new design model for interfaces to integrate both platforms while highlighting its performance results over the existing models. With the incorporation of off-chain data storage into the framework, overall scalability of the system can be increased. Finally, our research concludes how the proposed framework can be fused virtually into any existing IoT applications with minimal modifications.
In recent decades, the dramatic increase in global industrial activity has resulted in a significant rise in the use of fossil fuel energy resources, while technological progress has increased the carbon footprint and hence global warming. The significant increase in energy consumption caused by the Internet of Things (IoT) technology has created a new challenge and diverted our focus toward creating a more eco-friendly IoT ecosystem. The green IoT is an emerging field that has attracted a great deal of attention from researchers and industries, as it provides energy efficient services and enables the production and use of renewable energy. Meanwhile, blockchain technology has become a highly adoptable technology in the IoT and is attracting considerable interest from energy supply companies, business start-ups, financial institutions, governments and researchers. This study focuses on the role of the emerging blockchain technology in the green IoT ecosystem, presents the crucial factors that need to be taken into consideration in order to build a green IoT ecosystem, and discusses how blockchain technology contributes to make the IoT ecosystem greener. It also presents the open issues and future research directions to be considered when creating a sustainable green IoT ecosystem using blockchain technology.
Invoice financing has been a steadily growing component of the financing market as a whole for the last few years, and, in 2016, it became the third largest financing market. Nonetheless, the risk of frauds is still very high, and most solutions proposed so far are based on private, proprietary platforms that cannot match the global nature of such a market. Even the most recent proposals based on blockchain are mainly adopting a private, permissioned blockchain due to the lack of confidentiality in public blockchain. In this article, we propose an Invoice financing platform based on a public blockchain supporting both fully open and group-restricted auctioning of invoices. We addressed the confidentiality issue by storing the confidential data encrypted in IPFS and the corresponding hash in the smart contract hosted on Ethereum blockchain. Our blockchain-based solution ensures data confidentiality and benefits from the main properties of the public blockchain required in Invoice financing systems, such as transparency, immutability, trustworthiness, and security. Furthermore, our platform introduces a reputation system based on the past behavior of entities, computed using the blockchain global ledger. Such a reputation system allows insurance companies to modulate the cost of the insurance contracts they offer. This combination guarantees the complete transparency and tamperproofness of a public blockchain, while it allows reducing insurance costs and fraud possibilities.
MaurÃcio Moreira Neto, Carlos Sergio da S.Marinho, Emanuel Ferreira Coutinho, Leonardo O. Moreira · 6 authors
E-health applications are health-related computing solutions that use the internet to provide services to users. One of the main challenges of E-health applications is the data privacy and security of patients. E-health application need should provide security and privacy mechanisms due to sensitive user data such as medical exams, DNA sequences, and others. Blockchain technology has become a research focus on several sectors that require their inherent characteristics, especially, about the security and privacy of data. This paper aims to present research opportunities with the use of Blockchain technology in applications that manipulate DNA sequence data. For this purpose, we propose an architecture for general E-health applications with Blockchain and implement a Proof of Concept (POC) to analyze the use of Blockchain technology in E-health applications using DNA sequence data. We also listed a set of research opportunities that permeate this topic.