The fundamental problem in digital record-keeping is to establish consensus on an update to a ledger, e.g., a payment. Consensus must be achieved in the presence of faults—situations in which some computers are offline or fail to function appropriately. Traditional centralized record-keeping systems rely on trust in a single entity to achieve consensus. Blockchains decentralize record-keeping, dispensing with the need for trust in a single entity, but some instead build a consensus based on the wasteful expenditure of computational resources (proof-of-work). An ideal method of consensus would be tolerant to faults, avoid the waste of computational resources, and be capable of implementing all individually rational transfers of value among agents. We prove a Blockchain Trilemma: any method of consensus, be it centralized or decentralized, must give up (i) fault-tolerance, (ii) resource-efficiency, or (iii) full transferability.
The Blockchain is the newest and perspective technology in modern economy. This technology can help to solve different kind of problems in the industrial sphere, such as trust, transparency, security and reliability of data processing. In theory, the use of Blockchain technology shows great and positive results, but what can say about practice? In this paper the description of the Blockchain technology, and it advantages and disadvantages are analyzed. Many already implemented applications of Blockchain technology were studied, as well as affected success or problems factors during the implementations. This paper aim is to analyze conveniences and difficulties, related to the Blockchain integration and implementation in the different fields of modern industry.
As an emerging decentralized secure data management platform, blockchain has gained much popularity recently. To maintain a canonical state of blockchain data record, proof-of-work based consensus protocols provide the nodes, referred to as miners, in the network with incentives for confirming new block of transactions through a process of “block mining” by solving a cryptographic puzzle. Under the circumstance of limited local computing resources, e.g., mobile devices, it is natural for rational miners, i.e., consensus nodes, to offload computational tasks for proof of work to the cloud/fog computing servers. Therefore, we focus on the trading between the cloud/fog computing service provider and miners, and propose an auction-based market model for efficient computing resource allocation. In particular, we consider a proof-of-work based blockchain network, which is constrained by the computing resource and deployed as an infrastructure for decentralized data management applications. Due to the competition among miners in the blockchain network, the allocative externalities are particularly taken into account when designing the auction mechanisms. Specifically, we consider two bidding schemes: the constant-demand scheme where each miner bids for a fixed quantity of resources, and the multi-demand scheme where the miners can submit their preferable demands and bids. For the constant-demand bidding scheme, we propose an auction mechanism that achieves optimal social welfare. In the multi-demand bidding scheme, the social welfare maximization problem is NP-hard. Therefore, we design an approximate algorithm which guarantees the truthfulness, individual rationality and computational efficiency. Through extensive simulations, we show that our proposed auction mechanisms with the two bidding schemes can efficiently maximize the social welfare of the blockchain network and provide effective strategies for the cloud/fog computing service provider.
K. Clauson, Elizabeth A. Breeden, C. Davidson
et al.
Background: Effective supply chain management is a challenge in every sector, but in healthcare there is added complexity and risk as a compromised supply chain in healthcare can directly impact patient safety and health outcomes. One potential solution for improving security, integrity, data provenance, and functionality of the health supply chain is blockchain technology. Objectives: Provide an overview of the opportunities and challenges associated with blockchain adoption and deployment for the health supply chain, with a focus on the pharmaceutical supply, medical device and supplies, Internet of Healthy Things (IoHT), and public health sectors. Methods: A narrative review was conducted of the academic literature, grey literature, and industry publications, in addition to identifying and characterizing select stakeholders engaged in exploring blockchain solutions for the health supply chain. Results: Critical challenges in protecting the integrity of the health supply chain appear well suited for adoption of blockchain technology. Use cases are emerging, including using blockchain to combat counterfeit medicines, securing medical devices, optimizing functionality of IoHT, and improving the public health supply chain. Despite these clear opportunities, most blockchain initiatives remain in proof-of-concept or pilot phase. Conclusion: Blockchain technology has the unrealized promise to help improve the health supply chain, but further study, evaluation and alignment with policy mechanisms is needed. Keywords: Blockchain, Distributed Ledger, Pharmacy, Pharmaceutical, Supply chain
Can securities be settled on a blockchain, and, if so, what are the gains relative to existing settlement systems? The main benefit of a blockchain is faster and more flexible settlement, whereas settlement fails need to be ruled out where participants fork the chain to cancel trading losses. With a proof-of-work protocol, the blockchain needs to restrict settlement speed through block size and time in order to generate transaction fees, which finance costly mining. Despite mining being a deadweight cost, our estimates for the U.S. corporate debt market yield net gains from a blockchain in the range of 1–4 bps.Received May 31, 2017; editorial decision May 29, 2018 by Editor Itay Goldstein. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.
IoT is leading a digital revolution in both academia and industry. It brings convenience to people's daily lives; however, the issues of security and privacy of IoT become challenges. Blockchain, a decentralized database based on cryptographic techniques, is promising for IoT security, which may influence a variety of areas including manufacture, finance, and trading. The blockchain framework in an IoT system is an intriguing alternative to the traditional centralized model, which is struggling to meet some specified demands in IoT. In this article, we investigate typical security and privacy issues in IoT and develop a framework to integrate blockchain with IoT, which can provide great assurance for IoT data and various functionalities and desirable scalability including authentication, decentralized payment, and so on. We also suggest some possible solutions to these security and privacy issues in IoT based on blockchain and Ethereum to show how blockchain contributes to IoT.
The amount of computational power devoted to anonymous, decentralized blockchains such as Bitcoin's must simultaneously satisfy two conditions in equilibrium: (1) a zero-profit condition among miners, who engage in a rent-seeking competition for the prize associated with adding the next block to the chain; and (2) an incentive compatibility condition on the system's vulnerability to a “majority attack”, namely that the computational costs of such an attack must exceed the benefits. Together, these two equations imply that (3) the recurring, “flow”, payments to miners for running the blockchain must be large relative to the one-off, “stock”, benefits of attacking it. This is very expensive! The constraint is softer (i.e., stock versus stock) if both (i) the mining technology used to run the blockchain is both scarce and non-repurposable, and (ii) any majority attack is a “sabotage” in that it causes a collapse in the economic value of the blockchain; however, reliance on non-repurposable technology for security and vulnerability to sabotage each raise their own concerns, and point to specific collapse scenarios. In particular, the model suggests that Bitcoin would be majority attacked if it became sufficiently economically important — e.g., if it became a “store of value” akin to gold — which suggests that there are intrinsic economic limits to how economically important it can become in the first place.
<p>Poor water management has led to conflicts worldwide and significant loss of life and property. According to the UN, by 2040, nearly one in four children will live in an area with limited water resources. Poor water management has also been a critical factor in accelerating climate change. Climate change, in turn, intensifies extreme weather events, leading to more frequent and severe floods. The traditional water level monitoring stations are outdated, invasive, and limited in telemetry capabilities, resulting in numerous fatalities due to the lack of an effective early warning system. WAMO 300 (Water Monitor 300) introduces an innovative and noninvasive method of measuring water levels using navigation satellites such as GPS or Galileo, providing real-time alerts to various stakeholders. This study evaluates the feasibility of the WAMO 300 system and proposes decentralised water management solutions, leveraging this system to promote sustainable water diplomacy.</p>
Abstract Business modelling often involves extensive data collection and analysis, raising concerns about privacy infringement. Integrating Privacy Information Retrieval (PIR) mechanisms within business models is crucial to address privacy concerns, ensure compliance with regulations, safeguard sensitive data, and maintain trust with stakeholders; however, PIR is not included in the existing business models yet. In this paper, we propose the first decentralized business model that uses the PIR. We call our proposed model DEcentralized Business model with PIR (DEBPIR). DEBPIR uses a smart contract for PIR and encryption to share the privacy of classified information. We execute a thorough set of experiments on DEBPIR and evaluate the results based on privacy attainment, latency, and throughput. We also perform a comparative analysis between our proposed DEBPIR and the existing models; we observe that DEBPIR outperforms the existing models and provides $$95\%$$ 95 % privacy attainment. The latency and throughput of our proposed DEBPIR do not outgrow compared to the existing models. Thus, DEBPIR is an efficient solution for business models.
Electronic computers. Computer science, Information technology
Burhan Ul Islam Khan, Khang Wen Goh, Mohammad Shuaib Mir
et al.
As the Internet of Things (IoT) continues to revolutionize value-added services, its conventional architecture exhibits persistent scalability and security vulnerabilities, jeopardizing the trustworthiness of IoT-based services. These architectural limitations hinder the IoT’s Sensor-as-a-Service (SEaaS) model, which enables the commercial transmission of sensed data through cloud platforms. This study proposes an innovative computational framework that integrates decentralized blockchain technology into the IoT architectural design, specifically enhancing SEaaS efficiency. This research contributes to an optimized IoT architecture with decentralized blockchain operations and simplified public key encryption. Furthermore, this study introduces an advanced SEaaS model featuring innovative trading operations for sensed data among diverse stakeholders. At its core, this model presents a unique blockchain-based data-sharing mechanism that manages multiple aspects, from enrollment to validation. Evaluations conducted in a standard Python environment indicate that the proposed SEaaS model outperforms existing blockchain-based data-sharing models, demonstrating approximately 40% less energy consumption, 18% increased throughput, 16% reduced latency, and a 25% reduction in algorithm processing time. Ultimately, integrating a lightweight authentication mechanism using simplified public key cryptography within the blockchain establishes the model’s potential for efficient and secure data-sharing in IoT.
Blockchain has brought great potential in improving Space-Air-Ground Integrated Networks (SAGINs) in terms of security and efficiency. In blockchain-integrated SAGINs, many applications and services inherently require both the communication contents and communication behaviors to be secure against eavesdroppers, in which a covert communication algorithm is always deployed as a fundamental communication component. However, existing covert communication schemes suffer from critical problems. On the one hand, they require a sender to locally maintain a cryptographic key for a long period of time, which is very costly and inefficient to renew which means renewing the secret key. On the other hand, the ciphertext of covertly sent data would explicitly appear in the network, and thereby the schemes are vulnerable to secret key breach. In this paper, we propose a secure and efficient covert communication scheme for blockchain-integrated SAGINs, dubbed CC-BSAGINs, to free the sender from maintaining secret keys. The key technique is to map the covertly sent data to some transactions on the underlying blockchain in a secure and efficient way; the mapping information is sent via a covert communication algorithm. Such a two-step mechanism releases the sender from key management and does not require the ciphertext to be communicated. We provide formal security proofs and conduct a comprehensive performance evaluation, which demonstrates the security and efficiency of CC-BSAGINs.
Considering the global climate change and anticipation of water needs, this can pose significant problems. Trees play a crucial role in mitigating climate change, with the ability to assimilate carbon dioxide (CO2) and certain air pollutants, purify rainfall, and act as a barrier against soil erosion. This research focuses on the Bekasi River, which has a length of 6 km and a cross-sectional width of 65 meters. The data used is directly extracted from project data utilized for cost estimation, and data collection is conducted through interviews and questionnaires. The research methodology integrates Structural Equation Modeling-Partial Least Squares (SEM-PLS) as a data processing tool for survey and factor identification, along with Blockchain-Building Information Modeling (BIM) to assess the cost performance improvement of environmentally friendly reinforcement. Based on the test results, the utilization of BIM combined with blockchain technology can result in cost savings of 3.69% for the Improved level, 3.72% for the Enhanced level, 4.39% for the Superior level, 4.92% for the Conserving level, and 5.17% for the Restorative level in terms of cost enhancement.