A blockchain is a distributed transaction ledger, a disruptive technology that creates new possibilities for digital ecosystems. The blockchain ecosystem maintains an immutable transaction record to support many types of digital services. This paper compares the performance and scalability of a web-based groupware communication application using both non-blockchain and blockchain technologies. Scalability is measured where message load is synthesized over two typical communication topologies. The first is 1 to n network -- a typical client-server or star-topology with a central vertex (server) receiving all messages from the remaining n - 1 vertices (clients). The second is a more naturally occurring scale-free network topology, where multiple communication hubs are distributed throughout the network. System performance is tested with both blockchain and non-blockchain solutions using multiple cloud computing configurations. We analyze the empirical results from each configuration to identify the costs and overhead of blockchain technology.
Pietro Danzi, Anders E. Kalør, Čedomir Stefanović, Petar Popovski
Blockchain is a technology uniquely suited to support massive number of transactions and smart contracts within the Internet of Things (IoT) ecosystem, thanks to the decentralized accounting mechanism. In a blockchain network, the states of the accounts are stored and updated by the validator nodes, interconnected in a peer-to-peer fashion. IoT devices are characterized by relatively low computing capabilities and low power consumption, as well as sporadic and low-bandwidth wireless connectivity. An IoT device connects to one or more validator nodes to observe or modify the state of the accounts. In order to interact with the most recent state of accounts, a device needs to be synchronized with the blockchain copy stored by the validator nodes. In this work, we describe general architectures and synchronization protocols that enable synchronization of the IoT endpoints to the blockchain, with different communication costs and security levels. We model and analytically characterize the traffic generated by the synchronization protocols, and also investigate the power consumption and synchronization trade-off via numerical simulations. To the best of our knowledge, this is the first study that rigorously models the role of wireless connectivity in blockchain-powered IoT systems.
Tianyu Yang, Qinglai Guo, Xue‐Cheng Tai, Hongbin Sun · 7 authors
This paper presents the potential application of the blockchain technology in future Energy Internet operation, which would be more decentralized and self-executing. A blockchain system could solve several problems in the newly emerged scenarios with the support of the consensus mechanism, encryption methods and validation mechanism. Applying blockchains in decetralized operational framework of energy internet will bring the system with a more secure, flexible and low-cost operational solution.
Nowadays, Internet of Things (IoT) plays a vital role in various domains, which are home, agricultural, healthcare, tourism, transportation and education. The more of its development, the more we need to consider about its security and privacy issues. In this paper, we consider smart home system (SHS) as a case study. SHS is an integration of home appliances together with sensors to get automatic operations of heating, lighting, air conditioning, home security, health care systems, etc. Moreover, SHS allows homeowner to monitor and perform appliances functions remotely at any instant time via the Internet. Due to the widespread availability and proliferation of the SHS, attackers can impersonate as a homeowner to steal important data (e.g., vital signs) for doing extortion and life threatening. Therefore, in this paper, we present an approach of private Blockchain implementation for SHS to cope of its privacy and security issues. We review Ethereum Blockchain packages for SHS according to its smart contract features for handling access control policy, data storage and data flow management.
Ethereum, the well-known blockchain platform, does not have any limit for block size, unlike Bitcoin. However, there are other obstacles in processing unlimited transactions per second. Ethereum blockchain code runs by different clients, and they run on different speed and present the different level of performance. This paper studies Ethereum transactions and it analyzes two most popular Ethereum clients, Geth and Parity, on a private blockchain to obtain the better understanding of the effect of different clients on Ethereum performance. The results show that the transactions are 89.8 percent on average faster in Parity client in comparison with Geth client, using the same system configuration.
Mandrita Banerjee, Junghee Lee, Kim‐Kwang Raymond Choo
Internet of Things (IoT) devices are increasingly being found in civilian and military contexts, ranging from smart cities and smart grids to Internet-of-Medical-Things, Internet-of-Vehicles, Internet-of-Military-Things, Internet-of-Battlefield-Things, etc. In this paper, we survey articles presenting IoT security solutions published in English since January 2016. We make a number of observations, including the lack of publicly available IoT datasets that can be used by the research and practitioner communities. Given the potentially sensitive nature of IoT datasets, there is a need to develop a standard for sharing IoT datasets among the research and practitioner communities and other relevant stakeholders. Thus, we posit the potential for blockchain technology in facilitating secure sharing of IoT datasets (e.g., using blockchain to ensure the integrity of shared datasets) and securing IoT systems, before presenting two conceptual blockchain-based approaches. We then conclude this paper with nine potential research questions.
The blockchain technology is gaining momentum because of its possible application to other systems than the cryptocurrency one. Indeed, blockchain, as a de-centralized system based on a distributed digital ledger, can be utilized to securely manage any kind of assets, constructing a system that is independent of any authorization entity. In this paper, we briefly present blockchain and our work in progress, the VMOA blockchain, to secure virtual machine orchestration operations for cloud computing and network functions virtualization systems. Using tutorial examples, we describe our design choices and draw implementation plans.
With the promotion of electric power reform in China, distributed energy participating in power market transaction becomes possible. However, due to the characteristics of transaction decentralization, multiple energy synergies, information symmetry and the large quantity, the transaction cost and the risk of information leak increase significantly, which inhibits the enthusiasm of distributed energy to participate in electric power transaction. The block chain has been widely used in finance, logistics and other industries because of its decentralized data processing. In this paper, the characteristics and infrastructure of the block chain is analyzed and the distributed energy trading frame work based on the block chain is built. The result shows that block chain has significant effect on the information security of the energy transaction.
Bitcoin is a decentralized currency system that does not need any central authorities. All transactions issued by users have been recorded in the common ledger, called blockchain, which is shared by all users. In Bitcoin, an SPV (Simplified Payment Verification) client, which is a lightweight client that does not possess the entire blockchain, are developed for storage constrained devices such as a mobile phone. For an SPV client to check if there are transactions related to it, a Bloom filter where their Bitcoin addresses are involved is sent to a full client that possesses the entire blockchain. The full client only transfers transactions of which Bitcoin addresses are positive on the received Bloom filter. However, it is necessary to preserve the privacy of SPV clients when designing a Bloom filter because SPV clients' Bitcoin addresses will be identified by a full client with high probability. In this paper, we propose a privacy-preserving Bloom filter design for SPV clients based on γ-Deniability. γ-Deniability is a privacy metric that shows how much true positive Bitcoin addresses are hidden by the false positives in a Bloom filter. Furthermore, in order to design a Bloom Filter that satisfies a certain γ-Deniability, it is necessary to know the number of unique Bitcoin addresses that appear for the first time since the queried time. Based on our manual inspection, we propose to estimate it based on the linear regression. We show that our scheme achieves good estimation accuracy and γ through the simulation with a real Bitcoin blockchain.
In the year 2009, a new virtual currency called Bitcoin was introduced to the world. Bitcoin generation and transactions are based on hashes and asymmetric encryption algorithms. Bitcoin is the first attempt at creating a decentralized virtual currency with no central bank or financial entity controlling it and is very attractive to different demographies of users. A lot of misunderstanding and doubt surrounds Bitcoin. Based on studying the few years of Bitcoin's circulation and usage, we presented the strengths and weaknesses of Bitcoin and analyzed what opportunities and threats it faces in the current financial environment. We summarized the strengths, weaknesses, opportunities and threats for Bitcoin in an SWOT analysis. We concluded that the most important factors to influence the future of Bitcoin circulation and price are technological advances and people's openness to Bitcoin, the intervention of governments and financial powers by creating laws around cryptocurrencies and external events that are closely tied to the Bitcoin community.
After years of tremendous development and research in digital currency, the most famous Bitcoin industry chain has been gradually completed including mining, exchange, currency exchange, ATM, pervasive digital wallet design and so on. Especially, its blockchain technology has become FinTech organizations' emerging business and research directions, also been applied in the interdisciplinary medical science, supply chain and Internet of things. Digitizing currency can solve many problems in physical currency, such as the rampant counterfeit banknotes. Thus, not only the transparency can be cost-effectively preserved in store's ledger, but also customer's rights and interests can be protected while using the digital wallet. For the government, the regulation and auditing of financial transaction can be made simpler and more convenient for tax collection issue. Digitized transaction details can be much easier to audit by any computing device than manually audit the conventional ledger books. Furthermore, to make merchandise store to use digitized currency much easier, in this paper, we propose and deploy a Bitcoin collection supervision system called BPCSS based on blockchain technology with cloud databases for customers and merchandise stores. The preliminary experimental results via the well-known pervasive digital wallet of Testnet Bitcoin demonstrate the proposed BPCSS can cost-effectively collect payment and supervise the transactions between customer and merchandise store running the implemented NFC-enabled Android Apps.
Du Mingxiao, Xiaofeng Ma, Zhang Zhe, Xiangwei Wang · 5 authors
Blockchain is the basic technology of bitcoin. With the value appreciation and stable operation of bitcoin, blockchain is attracting more and more attention in many areas. Blockchain has the characteristics of decentralization, stability, security, and non-modifiability. It has the potential to change the network architecture. The consensus algorithm plays a crucial role in maintaining the safety and efficiency of blockchain. Using a right algorithm may bring a significant increase to the performance of blockchain application. In this paper, we reviewed the basic principles and characteristics of the consensus algorithms and analyzed the performance and application scenarios of different consensus mechanisms. We also gave a technical guidance of selecting a suitable consensus algorithm and summarized the limitations and future development of blockchain technology.
The recent expansion of the Internet of Things (IoT) and the consequent explosion in the volume of data produced by smart devices have led to the outsourcing of data to designated data centers. However, to manage these huge data stores, centralized data centers, such as cloud storage cannot afford auspicious way. There are many challenges that must be addressed in the traditional network architecture due to the rapid growth in the diversity and number of devices connected to the internet, which is not designed to provide high availability, real-time data delivery, scalability, security, resilience, and low latency. To address these issues, this paper proposes a novel blockchain-based distributed cloud architecture with a software defined networking (SDN) enable controller fog nodes at the edge of the network to meet the required design principles. The proposed model is a distributed cloud architecture based on blockchain technology, which provides low-cost, secure, and on-demand access to the most competitive computing infrastructures in an IoT network. By creating a distributed cloud infrastructure, the proposed model enables cost-effective high-performance computing. Furthermore, to bring computing resources to the edge of the IoT network and allow low latency access to large amounts of data in a secure manner, we provide a secure distributed fog node architecture that uses SDN and blockchain techniques. Fog nodes are distributed fog computing entities that allow the deployment of fog services, and are formed by multiple computing resources at the edge of the IoT network. We evaluated the performance of our proposed architecture and compared it with the existing models using various performance measures. The results of our evaluation show that performance is improved by reducing the induced delay, reducing the response time, increasing throughput, and the ability to detect real-time attacks in the IoT network with low performance overheads.
In the dusty, sunbaked land surrounding Ordos, a city in China's Inner Mongolia, sits one of the world's largest bitcoin mines. Encircled by coal-fired power plants, rare earth mineral extraction sites, and the skeletal remains of abandoned, half-constructed housing complexes, the Bitmain Technologies bitcoin mine is evidence of a new economic boom in the area. Every 10 minutes, a new block of data is added to the Bitcoin blockchain, the accounting ledger that records every transaction made with the currency. And every 10 minutes, a shiny new cache of bitcoins is deposited into the digital pocket of the person whose computer added the most recent block. Miners compete for the right to add new blocks by running a single calculation, the SHA-256 hash function, over and over as fast as they can. This essentially enters them into a lottery with all other miners on the network. The rewards of this lottery now amount to over US $8 million worth of bitcoins every day. Half of this goes to miners in China, who own a majority of the hashing power on the Bitcoin network, according to a new study by University of Cambridge researchers. Their proximity to manufacturers of specialized hardware and their access to cheap land and cheap electricity make Chinese miners the natural beneficiaries of the Bitcoin system, which rewards efficiency and hustle above all else.
Áron Lászka, Abhishek Dubey, Michael Walker, Douglas C. Schmidt
Power grids are undergoing major changes due to rapid growth in renewable energy resources and improvements in battery technology. While these changes enhance sustainability and efficiency, they also create significant management challenges as the complexity of power systems increases. To tackle these challenges, decentralized Internet-of-Things (IoT) solutions are emerging, which arrange local communities into transactive microgrids. Within a transactive microgrid, "prosumers" (i.e., consumers with energy generation and storage capabilities) can trade energy with each other, thereby smoothing the load on the main grid using local supply. It is hard, however, to provide security, safety, and privacy in a decentralized and transactive energy system. On the one hand, prosumers' personal information must be protected from their trade partners and the system operator. On the other hand, the system must be protected from careless or malicious trading, which could destabilize the entire grid. This paper describes Privacy-preserving Energy Transactions (PETra), which is a secure and safe solution for transactive microgrids that enables consumers to trade energy without sacrificing their privacy. PETra builds on distributed ledgers, such as blockchains, and provides anonymity for communication, bidding, and trading.
Transactive microgrids are emerging as a transformative solution for the\nproblems faced by distribution system operators due to an increase in the use\nof distributed energy resources and a rapid acceleration in renewable energy\ngeneration, such as wind and solar power. Distributed ledgers have recently\nfound widespread interest in this domain due to their ability to provide\ntransactional integrity across decentralized computing nodes. However, the\nexisting state of the art has not focused on the privacy preservation\nrequirement of these energy systems -- the transaction level data can provide\nmuch greater insights into a prosumer's behavior compared to smart meter data.\nThere are specific safety requirements in transactive microgrids to ensure the\nstability of the grid and to control the load. To fulfil these requirements,\nthe distribution system operator needs transaction information from the grid,\nwhich poses a further challenge to the privacy-goals. This problem is made\nworse by requirement for off-blockchain communication in these networks. In\nthis paper, we extend a recently developed trading workflow called PETra and\ndescribe our solution for communication and transactional anonymity.\n
Áron Lászka, Abhishek Dubey, Michael Walker, Douglas C. Schmidt
Power grids are undergoing major changes due to rapid growth in renewable\nenergy resources and improvements in battery technology. While these changes\nenhance sustainability and efficiency, they also create significant management\nchallenges as the complexity of power systems increases. To tackle these\nchallenges, decentralized Internet-of-Things (IoT) solutions are emerging,\nwhich arrange local communities into transactive microgrids. Within a\ntransactive microgrid, "prosumers" (i.e., consumers with energy generation and\nstorage capabilities) can trade energy with each other, thereby smoothing the\nload on the main grid using local supply. It is hard, however, to provide\nsecurity, safety, and privacy in a decentralized and transactive energy system.\nOn the one hand, prosumers' personal information must be protected from their\ntrade partners and the system operator. On the other hand, the system must be\nprotected from careless or malicious trading, which could destabilize the\nentire grid. This paper describes Privacy-preserving Energy Transactions\n(PETra), which is a secure and safe solution for transactive microgrids that\nenables consumers to trade energy without sacrificing their privacy. PETra\nbuilds on distributed ledgers, such as blockchains, and provides anonymity for\ncommunication, bidding, and trading.\n
Transactive microgrids are emerging as a transformative solution for the problems faced by distribution system operators due to an increase in the use of distributed energy resources and a rapid acceleration in renewable energy generation, such as wind and solar power. Distributed ledgers have recently found widespread interest in this domain due to their ability to provide transactional integrity across decentralized computing nodes. However, the existing state of the art has not focused on the privacy preservation requirement of these energy systems -- the transaction level data can provide much greater insights into a prosumer's behavior compared to smart meter data. There are specific safety requirements in transactive microgrids to ensure the stability of the grid and to control the load. To fulfil these requirements, the distribution system operator needs transaction information from the grid, which poses a further challenge to the privacy-goals. This problem is made worse by requirement for off-blockchain communication in these networks. In this paper, we extend a recently developed trading workflow called PETra and describe our solution for communication and transactional anonymity.
Blockchain is the latest buzzword in the FinTech scene and all companies big and small are vying to launch blockchain enabled products. At the basic technology level Blockchain is a distributed technology application. The challenges of operating such an application are known [1]. But the techniques of developing distributed applications by large enterprise teams, in a typical SDLC lifecycle (Develop, Test, Deploy and Upgrade) is not well known. Without proper methodologies / Formal Tools as is the case with most blockchain systems, bugs slip in easily. Studies on failures point to developers missing low handing bugs as most of the errors are simulated with 3 nodes or less [2]. The developer ecosystem is fast changing with technologies like containers and the emerging Micro Services architectures and Cloud Native Computing. The decisions on setup, build, CI/CD, Automated Testing are not taken at the beginning and as pointed out by [3] affect the entire project. The good news is that there are lot of tools available in the Open source domain that addresses the needs. The bad news is that picking the right combination to work in team sizes of 5 or more is not straight forward. This paper details our journey and lessons learnt on setting up Application Development Teams for Rapid Development in Blockchain using multiple blockchain tools like Ethereum and the HyperLedger Fabric. It details both our application architecture and the modifications needed to enable a Cloud Native architecture and the build/ deploy/ testing frameworks that we used.
Lei Xue, Yunlong Teng, Zhenyuan Zhang, Jianping Li · 6 authors
The problem is discussed that large grid fluctuation caused by distributed generation integration, pointing out that the microgrid power local consumption is a solution to this problem. However, power transaction volume of electricity in microgrid is not large, while management has not simplified, and labor cost is high. The introduction of power market can solve local consumption problem of microgrid. Using blockchain technology can simplify the management of microgrid power transactions and realize peer-to-peer power transaction. Microgrid dispatch centers can also be simplified. The purpose of this paper is to explore applications of blockchain technology related to electricity market on microgrid and to present a framework how blockchain is employed to facilitate peer-to-peer electricity sales in microgrid.
Recently, blockchains have been gathering a lot of interest. Many applications can benefit from the advantages of blockchains. Nevertheless, applications with more restricted privacy or participation requirements cannot rely on public blockchains. First, the whole blockchain can be downloaded at any time, thus making the data available to the public. Second, anyone can deploy a node, join the blockchain network and take part in the consensus building process. Private and consortium blockchains promise to combine the advantages of blockchains with stricter requirements on the participating entities. This is also the reason for the comparably small number of nodes that store and extend those blockchains. However, by targeting specific nodes, an attacker can influence how consensuses are reached and possibly even halt the blockchain operation. To provide additional security to the blockchain nodes, ChainGuard utilizes SDN functionalities to filter network traffic, thus implementing a firewall for blockchain applications. ChainGuard communicates with the blockchain nodes it guards to determine which origin of the traffic is legitimate. Packets from illegitimate sources are intercepted and thus cannot have an effect on the blockchain. As is shown with experiments, ChainGuard provides access control functionality and can effectively mitigate flooding attacks from several sources at once.
Purwono Purwono, Alfian Ma’arif, Wahyu Rahmaniar, Qazi Mazhar ul Haq · 6 authors
Blockchain technology has a promising future in a number of industries and enterprises. Formerly connected to virtual currency like Bitcoin, blockchain has evolved into a versatile technology with many applications. In the upcoming years, it is predicted that blockchain will revolutionize a variety of industries, including banking, supply chain management, healthcare, voting systems, and more. The future of blockchain technology depends critically on its ability to increase security and transparency. By providing a decentralized and unchangeable record, eliminating the need for middlemen, and boosting participant confidence, blockchain promotes secure and traceable transactions. This transparency has the potential to transform whole industries by reducing fraud, streamlining processes, and increasing output. Blockchain also has the power to change financial systems. Blockchain-based smart contracts facilitate faster, more efficient transactions by automating and enforcing contractual agreements without the need for middlemen. By enabling speedier cross-border transactions, reducing costs, and boosting financial inclusion, tokenization and blockchain-based digital currencies have the potential to overturn conventional banking institutions. Blockchain’s key attributes, including decentralization, transparency, immutability, and security, make it a desirable choice for a range of organizations. Cross-border payments, trade finance, and smart contracts are just a few of the financial sector processes that blockchain technology has the potential to enhance and automate, lowering costs and increasing productivity. Additionally, the tamper-resistance of blockchain technology can boost transaction security and reliability, allowing for a wider use in traditional financial institutions. Outside of the financial industry, blockchain technology has a lot of promise, particularly in industries like supply chain management, healthcare, energy, intellectual property, and governance. By enabling transparent and traceable transactions, blockchain may improve supply chain efficiency, ensure product authenticity, and boost customer trust. By facilitating the secure exchange of patient data and research data, the decentralized nature of blockchain technology can enhance data security, interoperability, and privacy in the healthcare sector. A more decentralized and sustainable energy ecosystem may be supported by blockchain technology through peer-to-peer energy exchange, grid management, and monitoring of renewable energy certificates in the energy sector. Additionally, blockchain technology has the potential to transform decentralized governance structures, voting procedures, intellectual property rights, and digital identity management. By allowing people to own and manage their digital identities, blockchain can enhance privacy and reduce identity theft. Blockchain-based voting systems can offer transparency, security, and verifiability, thereby increasing voter turnout and public trust in democratic institutions. Blockchain can also enable the secure and transparent management of intellectual property rights, fostering author credit and just compensation.