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Summary: Blockchain (BC) technology has been incorporated into the infrastructure of different kinds of applications that require transparency, reliability, security, and traceability. However, the BC still has privacy issues because of the possibility of privacy leaks when using publicly accessible transaction information, even with the security features offered by BCs. Specifically, certain BCs are implementing security mechanisms to address data privacy to prevent privacy issues, facilitates attack‐resistant digital data sharing and storage platforms. Hence, this proposed review aims to give a comprehensive overview of BC technology, to shed light on security issues related to BC, and to emphasize the privacy requirements for existing applications. Many proposed BC applications in asset distribution, data security, the financial industry, the Internet of Things, the healthcare sector, and AI have been explored in this article. It presents necessary background knowledge about BC and privacy strategies for obtaining these security features as part of the evaluation. This survey is expected to assist readers in acquiring a complete understanding of BC security and privacy in terms of approaches, ideas, attributes, and systems. Subsequently, the review presents the findings of different BC works, illustrating several efforts that tackled privacy and security issues. Further, the review offers a positive strategy for the previously described integration of BC for security applications, emphasizing its possible significant gaps and potential future development to promote BC research in the future. [ABSTRACT FROM AUTHOR]

Currently, the media industry is in the rapid development stage of media integration, which has brought about great changes in content production mode, presentation form, communication mechanism, operation and maintenance management, etc. At the same time, it is also faced with problems such as difficult information traceability, declining industry credibility, low data circulation quality and efficiency, difficult data security and user privacy protection, etc. Utilizing blockchain's characteristics can solve these problems that the media industry is currently facing. This paper designs a convergence media ecology model based on blockchain (CMEM-BC), focusing on the basic elements of the model, node operation and maintenance system, node management mechanism, value circulation mechanism, and storage mechanism, trying to establish a decentralized, traceable, and immutable convergence media ecosystem. On this basis, this paper summarizes the ecological framework and ecological model of CMEM-BC. Finally, the paper describes the verification of the effectiveness of CMEM-BC in key links through simulation experiments, verifying that CMEM-BC has high originality and is more suitable for the application of convergence media ecology through model analysis and comparison. [ABSTRACT FROM AUTHOR]

In order to solve the problem that allocating the whole virtual power station is not centralized and promoting the free access of power distribution, a research on distributed scheduling of urban power network based on blockchain technology is proposed. and a scheme is proposed. Based on the consistency of decentralized virtual power plant and blockchain in decentralized point-to-point interaction and decentralized cooperation, this paper proposes to use blockchain consensus mechanism to realize distributed scheduling of virtual power plant. According to the principle of continuous micro- increment cost, the optimal economic dispatch of virtual power system is realized by taking the micro- increment characteristic as the variable. and the optimal economic dispatch strategy is realized. As a node of the blockchain, each distributed energy in the virtual power plant has a complete backup of the key data of the whole network. When the load changes, each node uses the PBFT consensus algorithm to independently calculate the new power of each unit. The new power data is stored on the chain, and the global consistency of micro incremental features is maintained to realize the reasonable load distribution among units. The experimental results show that, when the initial t = 1, the λ the values of each unit are different. The system does not meet the principle of constant consumption micro-increase rate, and the system does not operate in the optimal state. After a PBFT consensus, λ variable reaches the same value at t=8, and the system reaches the optimal operating state. Conclusion: The simulation experiment verifies the effectiveness of the algorithm, realizes distributed scheduling by using blockchain, and provides a feasible reference scheme for the operation mode of decentralized virtual power plant. [ABSTRACT FROM AUTHOR]

The traditional methods of transporting goods and people in urban areas using vehicles powered by internal combustion engines are major contributors to pollution. As a result, an increasing number of logistics companies are transitioning to electric vehicles (EVs) for daily operations, replacing traditional engines. This shift opens research avenues regarding the integration of EVs into delivery workflows and how this can contribute to greener cities. This study tackles the EV routing problem, focusing on balancing battery constraints and optimizing routes. We formulated the problem as a pickup and delivery with time windows, incorporating electric energy consumption constraints, and utilized consensus mechanisms in an agent-based simulation context. Our evaluation used 15 scenarios, capturing variations in vehicle configurations, order generation rates, and battery and freight capacities. We compared two order allocation strategies: "Closest Allocation" and "Negotiation" consensus-based allocation. The results confirmed that the consensus-based strategy outperformed the "Closest Allocation" in metrics such as remaining orders, orders not handled in time, total distance traveled, total recharging cost, and total number of recharges. These findings have significant implications for urban planners, logistic companies, and policymakers, demonstrating that an agent-based simulation context for electric vehicles using consensus-based strategies can enhance delivery efficiency and promote sustainability. [ABSTRACT FROM AUTHOR]

Currently, Raft, as an mainstream consensus mechanism, has received widespread attention. Partition consensus can reduce the number of nodes involved in a single consensus and improve consensus efficiency. However, existing algorithms suffer from unreasonable partitioning and intolerance of Byzantine nodes. To address these problems, this paper proposes a novel Raft consensus algorithm combining comprehensive evaluation partitioning and Byzantine fault tolerance, CB-Raft. First, a comprehensive evaluation of nodes is conducted from the perspectives of consensus behavior and location, and the nodes are evenly divided based on the parity of the comprehensive ranking. Second, the leader is selected from the nodes with the top rankings in the comprehensive evaluation, and the nodes communicate with each other based on BLS signatures. Finally, a fast response mechanism based on cross-partition leader-follower communication is proposed to avoid the continued evil behavior of the leader, and a pipeline mechanism based on changeable signature thresholds is proposed to solve consensus blocking. The experimental results show that compared with the existing partitioning methods, the proposed partitioning scheme has significant advantages in terms of consensus latency, throughput, and the probability of partition success. Compared with the similar Raft algorithms, CB-Raft has high consensus performance and good resistance to Byzantine nodes. [ABSTRACT FROM AUTHOR]

The rapid increase in the number of computing intensive tasks has led to an overload of SMD (Smart Mobile Devices) computing tasks. By using MEC(Mobile Edge Computing Servers) and idle ED (Edge Devices) in the network, SMD with limited computing power can offload computing tasks to MEC and ED collaboration, and enhance system security based on the DPoR (Delegated Proof of Reputation) consensus mechanism. This study proposes a blockchain mobile edge computing offloading model based on BS AFSA (Bird Swarm Artificial Fish Swarm Algorithm), which transforms the task offloading problem into an optimization objective function to reduce the computational overhead. The improved BS AFSA is used to optimize the task delay and energy consumption, and the behavior parameters in the algorithm are constructed and the crowding factor is improved to elevate the local search accuracy in the later iteration. The simulation results show that compared with other benchmark algorithms, the proposed algorithm reduces the possibility of falling into local optimum and effectively reduces the total system cost of the joint offloading scheme. [ABSTRACT FROM AUTHOR]

Consensus mechanism (CM) is the heart and soul of blockchain, for it allows nodes in a blockchain network to reach an agreement on the state of system execution. Among the CMs, the right for constructing the next new block is regarded as the most important one since it is required for the blockchain to grow so that transaction data can be recorded in it. Proof-of-work (PoW) is an efficient CM since it allows all the nodes to participate equally in the competition for the right. However, high energy consumption makes PoW less desirable for applications. Moreover, application-oriented blockchains should employ CMs that could reflect some main characteristics of the applications to facilitate the development of other mechanisms, such as the incentive mechanisms. Proof-of-contribution (PoC) is an effective, application-oriented CM since the right for constructing the next new block is determined by contributions made by the nodes and the node that has accumulated the highest contribution value (CV) gets the right. PoC is a general-purpose CM since the behavior of nodes can be characterized in the form of contributions. However, the deterministic nature of PoC as the result of ranking nodes based on CVs may lower efficiency since nodes could fail to function due to network delay, node failure or node's simply dropping out of the network. This paper proposes to design highly effective and efficient CMs by integrating PoC with PoW, which we refer to as PoCW. In PoCW, nodes compete for the right for constructing the next new block based on PoW after being assigned different difficulty values (DVs) based on the ranking of their CVs. Since assigning DVs strictly according to the ranking of CVs would make PoCW resemble PoC while assigning the same DV to all the nodes would make PoCW the same as PoW, PoCW could be designed as a class of CMs through applying different DV assignment strategies to meet the effectiveness and efficiency requirements of a variety of applications. We can further apply the same principle at finer levels of granularity by dynamically grouping nodes along the ranking of CVs and then applying different DV assignment strategies to different groups. The paper will first describe a generic PoCW without involving node grouping and then present the design of a general PoCW through applying an example node grouping method to demonstrate the feasibility of PoCW as a general-purpose CM for blockchain-based applications. Experiments were also conducted to demonstrate the effectiveness and the efficiency of PoCW as well as its advantages over comparable CMs. [ABSTRACT FROM AUTHOR]

Public and permissionless blockchain systems are challenged by Sybil attacks, in which attackers use multiple identities to gain control. Traditionally, such attacks are prevented by consensus mechanisms relying on resource expenditure. However, such mechanisms (e.g. proof of work) face criticism for being wasteful. To address this and other concerns, novel blockchain systems backed by new consensus mechanisms have recently emerged. We formalise three key characteristics pursued by these systems: permissionlessness, Sybil attack resistance, and freeness. We demonstrate that no blockchain protocol can simultaneously achieve all three characteristics within the paradigm established by our formalisation. Thus, a trilemma emerges for distributed ledger technology designers, who must balance these characteristics thoughtfully. [ABSTRACT FROM AUTHOR]

In the upcoming era of transportation, a groundbreaking technology, known as vehicle-to-everything (V2X) communication, is poised to redefine our driving experience and revolutionize traffic management. Real-time and secure communication plays a pivotal role in V2X networks, with the decision-making process being a key factor in establishing communication and determining malicious nodes. The proposed framework utilizes a directed acyclic graph (DAG) to facilitate real-time processing and expedite decision-making. This innovative approach ensures seamless connectivity among vehicles, the surrounding infrastructure, and various entities. To enhance communication efficiency, the entire roadside unit (RSU) region can be subdivided into various sub-regions, allowing RSUs to monitor and govern each sub-region. This strategic approach significantly reduces transaction approval time, thereby improving real-time communication. The framework incorporates a consensus mechanism to ensure robust security, even in the presence of malicious nodes. Recognizing the dynamic nature of V2X networks, the addition and removal of nodes are aligned. Communication latency is minimized through the deployment of computational resources near the data source and leveraging edge computing. This feature provides invaluable recommendations during critical situations that demand swift decision-making. The proposed architecture is further validated using the "veins" simulation tool. Simulation results demonstrate a remarkable success rate exceeding 95%, coupled with a significantly reduced consensus time compared to prevailing methodologies. This comprehensive approach not only addresses the evolving requirements of secure V2X communication but also substantiates practical success through simulation, laying the foundation for a transformative era in transportation. [ABSTRACT FROM AUTHOR]

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The number of cyberattacks has increased significantly, necessitating the establishment of robust safeguards. To protect networks from intrusion, Cybersecurity Threat Intelligence (CTI) has been employed. CTI must effectively counter these attacks. Sharing CTI is essential for understanding threats, safeguarding assets, and blocking attack vectors. However, conventional CTI faces challenges related to privacy concerns, negative publicity, and issues with quality, which hinder the sharing of threats within the CTI community. This paper introduces a new framework that leverages Blockchain technology to enhance CTI frameworks. We developed a consensus algorithm combining Proof of Work (PoW) and Proof of Stake (PoS) methodologies to maintain CTI network security. This hybrid system requires miners to stake tokens in proportion to their hashing power, aligning incentives with network integrity and defending against double spending attacks. Our framework employs Blockchain features such as privacy, and digital signatures to create a secure and private environment for CTI sharing. We evaluated the effective hash power distribution and discussed the advantages, limitations, and potential improvements for the CTIB mode. The model was tested against 51% attacks, proving its effectiveness statistically. Implementing this Blockchain & CTI algorithm will pave the way for a more resilient and equitable cybersecurity defense mechanism. [ABSTRACT FROM AUTHOR]

This work introduces a blockchain-based secure medical prescription-management system seamlessly integrated with a dynamic Internet of Things (IoT) framework. Notably, this integration constitutes a pivotal challenge in the arena of resource-constrained IoT devices: energy consumption. The choice of a suitable blockchain consensus mechanism emerges as the linchpin in surmounting this hurdle. Thus, this paper conducts a comprehensive comparison of energy consumption between two distinct consensus mechanisms: Proof of Work (PoW) and Quorum-based Byzantine fault tolerance (QBFT). Furthermore, an assessment of the most energy-efficient algorithm is performed across multiple networks and various parameters. This approach ensures the acquisition of reliable and statistically significant data, enabling meaningful conclusions to be drawn about the system's performance in real-world scenarios. The experimental results show that, compared to the PoW, the QBFT consensus mechanism reduced the energy consumption by an average of 5%. This finding underscores the significant advantage of QBFT in addressing the energy consumption challenges posed by resource-constrained IoT devices. In addition to its inherent benefits of privacy and block time efficiency, the Quorum blockchain emerges as a more sustainable choice for IoT applications due to its lower power consumption. [ABSTRACT FROM AUTHOR]

Blockchain systems allow for securely keeping shared records of transactions in a decentralised way. This is enabled by algorithms called consensus mechanisms. Proof-of-work is the most prominent consensus mechanism, but environmentally unsustainable. Here, we focus on proof-of-stake, its best-known alternative. Importantly, decentralised decision-making power is not an inherent feature of blockchain systems, but a technological possibility. Numerous security incidents illustrate that decentralised control cannot be taken for granted. We therefore study how key parameters affect the degree of decentralisation in proof-of-stake blockchain systems. Based on a real-world implementation of a proof-of-stake blockchain system, we conduct agent-based simulations to study how a range of parameters impact decentralisation. The results suggest that high numbers of initial potential validator nodes, large transactions, a high number of transactions, and a very high or very low positive validator network growth rate increase decentralisation. We find weak support for an impact of changes in transaction fees and initial stake distributions. Our study highlights how blockchain challenges our understanding of decentralisation in information systems research, and contributes to understanding the governance mechanisms that lead to decentralisation in proof-of-stake blockchain systems as well as to designing proof-of-stake blockchain systems that are prone to decentralisation and therefore more secure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of National University of Defense Technology / Guofang Keji Daxue Xuebao is the property of NUDT Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the invention of Internet-enabled devices, cloud and blockchain-based technologies, an online voting system can smoothly carry out election processes. During pandemic situations, citizens tend to develop panic about mass gatherings, which may influence the decrease in the number of votes. This urges a reliable, flexible, transparent, secure, and cost-effective voting system. The proposed online voting system using cloud-based hybrid blockchain technology eradicates the flaws that persist in the existing voting system, and it is carried out in three phases: the registration phase, vote casting phase and vote counting phase. A timestamp-based authentication protocol with digital signature validates voters and candidates during the registration and vote casting phases. Using smart contracts, third-party interventions are eliminated, and the transactions are secured in the blockchain network. Finally, to provide accurate voting results, the practical Byzantine fault tolerance (PBFT) consensus mechanism is adopted to ensure that the vote has not been modified or corrupted. Hence, the overall performance of the proposed system is significantly better than that of the existing system. Further performance was analyzed based on authentication delay, vote alteration, response time, and latency.

Direct air capture (DAC) is a critical and emerging Negative Emissions Technology (NET) that directly removes CO2 from the atmosphere, significantly contributing to climate change. However, the deployment and management of large-scale DAC faces challenges such as collections and analysis of energy consumption data, intricate device and system management, emission prediction and operation strategy, precise carbon footprint tracking, etc. This paper proposes the integration of blockchain technology with DAC systems to address these challenges, utilizing blockchain's inherent properties of immutability, security, and transparency. The implementation strategy includes the development of a DAC consortium blockchain system, leveraging a consensus mechanism,11 Consensus mechanism: The programming and process used in blockchain systems to achieve distributed agreement about the ledger's state or the state of a data set. (Source: Investopedia) ECDSA encryption,22 Elliptic Curve Digital Signature Algorithm (ECDSA): In cryptography, the Elliptic Curve Digital Signature Algorithm (ECDSA) offers a variant of the Digital Signature Algorithm (DSA) which uses elliptic-curve cryptography. As with elliptic-curve cryptography in general, the bit size of the private key believed to be needed for ECDSA is about twice the size of the security level, in bits. (Source: Wikipedia) IoT33 Internet of things (IoT): describes devices with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other communication networks. (Source: Wikipedia) integration, and digital signatures. Preliminary modeling of the proposed system suggests potential improvements in operational efficiency and a reduction in data inaccuracies. The proposed system underscores the system's ability to streamline identity verification, improve data collection accuracy, and facilitate secure, confidential information sharing among DAC stakeholders. By enhancing the efficiency and reliability of DAC operations, this approach supports the scalable and effective deployment of NETs in the global effort to combat climate change. Future research will focus on empirical validation through pilot projects and simulations to further substantiate these claims.

Currently, in the blockchain-based distributed microgrid trading system, there are some problems, such as low throughput, high delay, and a high communication overhead. To this end, an improved Practical Byzantine Fault Tolerance (PBFT) algorithm (CE-PBFT) suitable for microgrid power trading is proposed. First, a node credit value calculation model is introduced, and nodes are divided into consensus, supervisory, and propagation nodes according to their credit values, forming a hierarchical network structure to ensure the efficiency and reliability of consensus. Secondly, the consensus process is optimized by adopting a segmented consensus mechanism. This approach calculates the consensus rounds for nodes and selects the methods for node-type switching and consensus based on these calculations, reaching dynamic changes in node states and credit values, effectively reducing the communication overhead of node consensus. Finally, the experiments show that compared with the IMPBFT and PBFT algorithms, the CE-PBFT algorithm has better performance in throughput, delay, and communication overhead, with a 22% higher average throughput and 15% lower average delay than the IMPBFT algorithm and a 118% higher average throughput and 87% lower average delay than the PBFT algorithm. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Blockchain technology provides a reliable information access environment for the Internet of Vehicles, but the high latency and complex computing consensus mechanism in blockchain make it difficult to port to onboard devices. Recently, there are many methods to reduce the time cost of consensus by optimizing node grouping or reducing redundant calculations, but this would lower the security level of the blockchain. To address these issues and reduce the adverse effects of frequently changing channel quality on consensus results, a consensus mechanism based on vehicle comprehensive state factors for nodes selection (PoMS) is proposed. Firstly, the vehicle nodes utilize the machine learning model to predict local driving parameters and broadcast the predicted results to the other nodes. Secondly, each node uses interactive data to calculate the state values, and the leader comprehensively evaluates the nodes participating in the consensus and selects the nodes as relays. Finally, we also adopted a double-layer blockchain structure to accelerate the selection process of relay nodes. In order to verify the performance of the proposed consensus algorithm, we conducted tests on transmission time and communication quality. The experimental results show that compared to traditional consensus mechanisms, the algorithm proposed in this paper can reduce time overhead by an average of 12.7% and maintain a good transmission rates under a certain number of malicious nodes. [ABSTRACT FROM AUTHOR]

With the invention of Internet-enabled devices, cloud and blockchain-based technologies, an online voting system can smoothly carry out election processes. During pandemic situations, citizens tend to develop panic about mass gatherings, which may influence the decrease in the number of votes. This urges a reliable, flexible, transparent, secure, and cost-effective voting system. The proposed online voting system using cloud-based hybrid blockchain technology eradicates the flaws that persist in the existing voting system, and it is carried out in three phases: the registration phase, vote casting phase and vote counting phase. A timestamp-based authentication protocol with digital signature validates voters and candidates during the registration and vote casting phases. Using smart contracts, third-party interventions are eliminated, and the transactions are secured in the blockchain network. Finally, to provide accurate voting results, the practical Byzantine fault tolerance (PBFT) consensus mechanism is adopted to ensure that the vote has not been modified or corrupted. Hence, the overall performance of the proposed system is significantly better than that of the existing system. Further performance was analyzed based on authentication delay, vote alteration, response time, and latency. [ABSTRACT FROM AUTHOR]

The rapid development of network technology makes the implementation of ubiquitous tasks possible in which the Flying Ad-Hoc Network(FANET) plays an important role. Control stations distributed in different task areas can control UAVs in FANET to complete a complex task. However, the application of FANET brings about problems of identity security and data security. Attackers can impersonate legal entities to issue fake commands or modify task data, which will hinder the smooth execution of tasks. The existing centralized entity authorization method has the single point of failure problem, and the distributed method based on the blockchain does not consider the entity security and data security issues at the task level. Therefore, to protect the entity identity security and task data security of ubiquitous tasks in FANET, in this paper, we propose a blockchain-based ubiquitous entity authorization and management scheme (BUAMH), which uses smart contracts and homomorphic encryption technology to achieve entity registration, access control and dynamic task member management. Specifically, the blockchain is used to record and protect entity behavior information and the results of smart contracts. Five smart contracts are designed to realize the authorization and management of entity identity. Besides, Homomorphic encryption technology is used to manage UAVs while protecting entity privacy. Furthermore, a side-chain structure is constructed and an identity consensus mechanism(ICM) is proposed to manage multi tasks and speed up the consensus of miners, respectively. The experimental results show that the computational costs and communication costs of the proposed BUAMH are superior to the existing technology. [ABSTRACT FROM AUTHOR]

As an important part of the smart grid (SG), Vehicle-to-Grid (V2G) has significantly advanced the development of the grid. However, the open nature of V2G system itself and the deployment of charging piles (CPs) increase the difficulty of terminal control and leave the grid vulnerable to attacks. The existing security schemes of V2G mostly consider the threat of external attacks and conduct defense strategies such as identity authentication and key management, which cannot resist internal attacks initiated by selfish or captured terminals that have passed authentication. In this paper, we propose a lightweight block-chain-based trust management method for V2G terminals. Specifically, we provide a blockchain-based V2G trust management architecture. A V2G terminal adaptive trust calculation model based on information entropy is established, which provides a basis for accurate trust calculation. Considering that, although the on-chain data is tamper-proof, the existing blockchain technology lacks the means to verify the authenticity of the source data before it is uploaded to the chain, a new blockchain consensus mechanism is designed. Wherein five consensus guidelines ensure that only real trust parameters can be written on the chain. In this way, malicious terminals can be identified by consensus screening and trust calculation, thereby taking control measures. Moreover, to avoid redundant hash operations during the trust parameter upload process, Merkle Mountain Range (MMR) is introduced to optimize the block structure. The experimental results show that in comparison to existing methods, LVTM is very resistant to internal attacks, and has lower communication costs and computing overhead.

In the era of the Fourth Industrial Revolution (Industry 4.0), blockchain technology emerges as an innovative solution to address the challenges of digital-based business networks, such as traceability, transparency, trust, and data authenticity. This transformative technology has shown promise across diverse domains, including finance, healthcare, and supply chain, by enabling secure data transmission and trust establishment between entities. However, blockchain technology experiences an inherent trade-off issue between the core properties of security, decentralization, and scalability in its type of network. While permissionless blockchain excels in security and decentralization, such networks lack scalability and suitability for business transactions. Conversely, permissioned blockchains offer better performance, but are vulnerable to cyber-attacks due to weaknesses in consensus mechanisms. Therefore, this paper provides an analysis of blockchain technology, emphasizing the pivotal role of consensus mechanisms in ensuring security and system performance. In addition, it identifies practical threats, suggests countermeasures, and underscores the importance of resilient and secure consensus mechanisms. Furthermore, it compares and analyzes existing mechanisms for permissioned blockchains, discusses their limitations, and highlights the significance of ensuring system security and performance. Finally, it uncovers essential factors to consider when designing consensus mechanisms for specific blockchain-based applications, laying the foundation for future research in practical and secure permissioned blockchain applications.

Conventional centralized optimization and management approaches may not work well in an emerging and distributed energy system with a high penetration of electric vehicles and green energy sources. The usage of blockchain technology is growing as a strong competitor as it can provide this kind of market with a transparent, secure, and efficient transactional platform. Nevertheless, most energy systems usually depend on complex mathematical optimization, which is poorly incorporated into blockchain applications. Moreover, time-sensitive message dissemination requirements, resource-intensiveness, high computational load, and communication overhead of the traditional blockchain consensus mechanisms make it difficult to connect with real-time vehicular networks. Here, we employ Proof of Intelligence (PoI), a novel prosumer-centric blockchain consensus mechanism to develop a comprehensive model of trust based on commitments of supply and demand through the application of peer-to-peer energy exchange with effective and dynamic integration of renewable sources and electric vehicles both in the day ahead and real-time energy trading platforms. Additionally, the PoI smart contract is developed to seamlessly incorporate mathematical optimization with an increased level of security, scalability, throughput, and low confirmation latency of transactions achieved through the reduced effort involved in finding and confirming the optimal solution in comparison with conventional blockchain consensus mechanisms.

Aiming at the challenges faced by the combination of blockchain and mobile ad hoc networks, a system model DAGGraph based on DAG (directed acyclic graph) is proposed, which adopts the DAG structure to adapt to the network split caused by mobility. Firstly, the clustering algorithm is optimized, and an algorithm for limiting the density of nodes in the cluster is proposed, which effectively solves the problem of throughput reduction and energy consumption increase caused by the uncontrolled increase of the number of nodes in the cluster. Secondly, for network splitting and merging caused by the rapid movement of the nodes, a block recovery algorithm based on data synchronization between cluster heads is proposed. The legal blocks generated by all nodes are preserved through DAG. When the network is merged, the original cluster heads exchange their generated block branches, realizing the recovery of the block branches. Finally, a simplified block appending algorithm is proposed, which simplifies the block appending process on the premise that the internal nodes are trusted, reduces the error caused by block propagation in the mobile environment, shortens the block confirmation time, and improves the system throughput. Security analysis shows that DAGGraph can resist common attacks against blockchain, and resist denial-of-service attacks against mobile ad hoc networks. Simulation results show that the latency and throughput of DAGGraph are better than existing IoT blockchain solutions in most cases.

Human bone microarchitecture is complex and density-based bone assessment modalities cannot fully capture bone strength or health. Ultrasound can be used to assess bone microstructure, but it is hindered by the dense and acoustically diverse nature of cortical bone. This study proposes a methodology for predicting cortical bone thickness and porosity through a novel approach utilizing convolutional neural networks (CNNs), processing multi-frequency radiofrequency (RF) data obtained from ultrafast ultrasound, and implementing a consensus mechanism to enhance reliability. Received ultrasound RF signals are processed using a CNN with a mutual consensus mechanism, which is used to discard received RF data when measurement variation is over a certain threshold. The feasibility of the proposed method is demonstrated through realistic simulations and an ex vivo animal bone study using an ultrafast ultrasound scanner. The preliminary findings of this study demonstrate an enhancement in overall accuracy, with an increase from 92% to 95.6% for thickness and an increase from 73.4% to 88.4% for porosity classification, without and with consensus respectively. The implemented mutual consensus mechanism increases the accuracy of the thickness and porosity estimations both in silico and ex vivo. Ultrafast ultrasound scanners can capture thousands of RF signals within seconds, which results in availability of large datasets for implementation of artificial intelligence and machine learning algorithms. Here, we propose a new approach for ultrafast ultrasound data processing that values data quality over quantity by discarding noisy measurements using a consensus mechanism to improve the final estimation reliability.

Blockchain, a distributed and digital ledger technology, has the potential to transform several industries from cryptocurrencies to supply chains. However, the complexity of understanding the technology can be a challenge for most people, especially for newcomers. This study paper aims to provide an in-depth analysis and review of the different layers including the data, network, consensus, smart contract, and application layers. In this paper, we performed an in-depth analysis and review of the components of each layer. We also tried to simulate different consensus algorithms so a reader can understand which blockchain consensus algorithm can be chosen for a specific application. By reading this paper, a reader can understand the blockchain architecture and choose the right algorithms, languages and protocols for building their own blockchain network. The paper also addresses the challenges and difficulties of building a sustainable and secure blockchain. We believe that the choice of consensus algorithm is the most important thing for sustainability in a blockchain network. We show that some consensus algorithms use much more energy than others, and we suggest that developers choose consensus algorithms that use less energy. This paper is a great resource for anyone who wants to learn more about blockchain architecture and consensus algorithms. It gives a complete review of the subject and talks about the difficulties of making a blockchain that will be secure and sustainable. Researchers, developers, and anyone else interested in the future of blockchain technology will be interested in this study.

In modern cities, consumers with distributed energy resources (DERs) can trade energy by managing their consumption and supply. Blockchain is considered to provide technical support for establishing a distributed energy market, while the current mainstream blockchain technology cannot meet the requirement of efficiency and scalability under such a transaction scenario. In addition, the potential defaults of market players also hinder market implementation. Therefore, a reputation-based distributed energy trading mechanism and the corresponding blockchain consensus method considering reputation management are proposed in this paper. Firstly, a distributed reputation management mechanism is designed to systematically evaluate the user’s behavior in the market. Secondly, to address the limitations of traditional consensus methods in the distributed energy market distributed reputation control is introduced into the node model of blockchain, and a new energy blockchain consensus method named DPoR is proposed to solve the technical bottleneck under the distributed energy trading scenario. We also present a corresponding transaction mechanism to encourage market participants to maintain their reputations. Finally, the simulation results verify the effectiveness of the proposed transaction mechanism in this paper, and the presented blockchain consensus mechanism can meet the performance requirements under distributed energy trading scenarios in terms of high efficiency, low consumption, and openness.

In this paper, a novel Elliptic Crypt with Secured Blockchain-backed Federated Q-Learning Framework is proposed to offer an intelligent healthcare system that mitigates the attacks and data misused by malicious intruders. Initially, the entered IoMT data is collected from publicly available datasets and encrypted using the Extended Elliptic Curve Cryptography (E_ECurCrypt) technique for ensuring the security. This encrypted data is fed as an input to the blockchain-powered collaborative learning model. Here, the federated Q-learning model trains the inputs and analyzes the presented attacks to ensure better privacy protection. Afterwards, the data is securely stored in decentralized blockchain technology. Subsequently, an effective Delegated Proof of Stake (Del_PoS) consensus algorithm is used to validate the proposed framework. The experiment is conducted using the WUSTL-EHMS-2020 dataset and the performances are analyzed by evaluating multiple matrices and compared to other existing methods. The performance of the proposed framework can be assessed using multiple matrices and the results will be compared to other existing methods. As a result, the proposed method has achieved 99.23% accuracy, 98.42% precision, 98.12% recall, 98.27% F1 score, 59080.506 average throughput, 59080.506 average decryption time 1.94 seconds and an average encryption time of 1.84 seconds and are superior to conventional methods.

Currently, the media industry is in the rapid development stage of media integration, which has brought about great changes in content production mode, presentation form, communication mechanism, operation and maintenance management, etc. At the same time, it is also faced with problems such as difficult information traceability, declining industry credibility, low data circulation quality and efficiency, difficult data security and user privacy protection, etc. Utilizing blockchain’s characteristics can solve these problems that the media industry is currently facing. This paper designs a convergence media ecology model based on blockchain (CMEM-BC), focusing on the basic elements of the model, node operation and maintenance system, node management mechanism, value circulation mechanism, and storage mechanism, trying to establish a decentralized, traceable, and immutable convergence media ecosystem. On this basis, this paper summarizes the ecological framework and ecological model of CMEM-BC. Finally, the paper describes the verification of the effectiveness of CMEM-BC in key links through simulation experiments, verifying that CMEM-BC has high originality and is more suitable for the application of convergence media ecology through model analysis and comparison.

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Blockchain, with its disruptive innovative technology, is continuously changing the operational rules and application scenarios of various industries such as digital finance, digital government, Internet of Things, and intelligent manufacturing. It is an indispensable key technology for building a new trust and value system in the future society. However, due to the defects of its own technology and the complexity and diversity of application scenarios, the security issues of blockchain are becoming increasingly serious. Security has become a major bottleneck restricting the future development of blockchain, and the road to blockchain regulation is arduous. This paper introduces the background knowledge, basic concepts, and architecture of blockchain. Starting from the architecture of blockchain, it analyzes the security issues and prevention strategies of blockchain from seven aspects: data layer, network layer, consensus layer, incentive layer, contract layer, application layer, and cross-chain. Based on this, it discusses the safety supervision of blockchain from the current situation and difficulties of policy supervision, the establishment of technical supervision standards, innovative methods, and development trends. [ABSTRACT FROM AUTHOR]

Federated learning is a revolutionary deep learning model, and it enables users to train the global model cooperatively without exposing their private data. However, some malicious clients can lead to the risk of single point of failure and privacy disclosure, this poses a serious threat to the security of federated learning. In response to the above issues, based on the existing research, this article proposed a blockchain empowered multi edge federated learning model. Firstly, this paper proposed to use blockchain instead of central server to enhance the stability and reliability of model training process; Secondly, this paper proposed a consensus mechanism based on edge computing to achieve a more efficient consensus process; In addition, incorporating reputation assessment into the federated learning training process can transparently measure the contribution value of each participant and standardize the behavior of work nodes. Finally, comparative experiments show that the scheme can maintain high accuracy in the malicious environment, and can resist higher malicious ratio compared with the traditional federated learning algorithm. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Frontiers of Computer Science & Technology is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Computer Engineering & Applications is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The consensus mechanism is a critical technology in the power trading blockchain distributed power trading platforms, which are gradually being applied and promoted to achieve the "dual carbon" goal. Green-certificate trading and carbon emission trading systems help mobilize power generation enterprises to increase the generation of and investment in renewable energy, thereby becoming important factors in distributed power trading. Therefore, they should also be considered as factors in the consensus mechanism. This article first evaluates the green-certificate weight based on whether nodes possess green certificates, evaluates the carbon emission weight based on the carbon emission settlement of nodes in the previous cycle, and constructs a mechanism to evaluate a node's weight. An improved Raft consensus algorithm based on node weight is then proposed. Nodes with greater weights are more likely to become leading nodes, promoting active compliance and green consumption by nodes and reducing carbon emissions. A simulation shows that the improved Raft consensus mechanism enhances the reliability of leading nodes, improves the efficiency of the distributed power transaction, increases the generation of renewable energy, and encourages the consumption of new energy. [ABSTRACT FROM AUTHOR]

Small and medium enterprises (SMEs) contribute to strengthening the global market by creating new jobs. Interactions among these companies may indeed be facilitated via e-commerce platforms. However, e-commerce activities seem to be a virtual face-to-face transactions, highly digital, and mutable. E-commerce based SMEs are frequently exposed to virtuous risks and competitive intensity. Blockchain is a digital database with the features of truthfulness, assurance, accountability, and intractability. It is made up of decentralized data storage, a consensus algorithm, and smart contracts. As a result, integrating e-commerce platforms and blockchain networks to help SMEs overcome their security difficulties. Conventional e-commerce platforms and storage depends on authorized intermediary networks or distributed cloud storage. Still, the failure of a single device is a danger, and third parties access, and data storage systems might be subject to data theft attacks. This paper presents a proof-of-authority (PoA) based consensus mechanism for e-commerce platforms in SMEs to address security issues in the network. This manuscript initially developed an energy-efficient PoA based consensus mechanism supported by e-commerce platforms for SMEs. We construct a comprehensive PoA consensus model based on pseudorandom number generator (PRNG) and accumulated validators number (AVN) for adding a new block in the conceptual framework. Finally, we demonstrate the security performance of the proposed consensus mechanism to help SMEs solve finance and trading issues. To evaluate the energy performance of the proposed model, we did a CPU utilization analysis and compared it with existing consensus protocols.

The traditional methods of transporting goods and people in urban areas using vehicles powered by internal combustion engines are major contributors to pollution. As a result, an increasing number of logistics companies are transitioning to electric vehicles (EVs) for daily operations, replacing traditional engines. This shift opens research avenues regarding the integration of EVs into delivery workflows and how this can contribute to greener cities. This study tackles the EV routing problem, focusing on balancing battery constraints and optimizing routes. We formulated the problem as a pickup and delivery with time windows, incorporating electric energy consumption constraints, and utilized consensus mechanisms in an agent-based simulation context. Our evaluation used 15 scenarios, capturing variations in vehicle configurations, order generation rates, and battery and freight capacities. We compared two order allocation strategies: “Closest Allocation” and “Negotiation” consensus-based allocation. The results confirmed that the consensus-based strategy outperformed the “Closest Allocation” in metrics such as remaining orders, orders not handled in time, total distance traveled, total recharging cost, and total number of recharges. These findings have significant implications for urban planners, logistic companies, and policymakers, demonstrating that an agent-based simulation context for electric vehicles using consensus-based strategies can enhance delivery efficiency and promote sustainability.

This work introduces a blockchain-based secure medical prescription-management system seamlessly integrated with a dynamic Internet of Things (IoT) framework. Notably, this integration constitutes a pivotal challenge in the arena of resource-constrained IoT devices: energy consumption. The choice of a suitable blockchain consensus mechanism emerges as the linchpin in surmounting this hurdle. Thus, this paper conducts a comprehensive comparison of energy consumption between two distinct consensus mechanisms: Proof of Work (PoW) and Quorum-based Byzantine fault tolerance (QBFT). Furthermore, an assessment of the most energy-efficient algorithm is performed across multiple networks and various parameters. This approach ensures the acquisition of reliable and statistically significant data, enabling meaningful conclusions to be drawn about the system’s performance in real-world scenarios. The experimental results show that, compared to the PoW, the QBFT consensus mechanism reduced the energy consumption by an average of 5%. This finding underscores the significant advantage of QBFT in addressing the energy consumption challenges posed by resource-constrained IoT devices. In addition to its inherent benefits of privacy and block time efficiency, the Quorum blockchain emerges as a more sustainable choice for IoT applications due to its lower power consumption.