There are a series of challenges in microgrid transactions, and blockchain technology holds the promise of addressing these challenges. However, with the increasing number of users in microgrid transactions, existing ...
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There are a series of challenges in microgrid transactions, and blockchain technology holds the promise of addressing these challenges. However, with the increasing number of users in microgrid transactions, existing blockchain systems may struggle to meet the growing demands for transactions. Therefore, this paper proposes an efficient and secure blockchain consensus algorithm designed to meet the demands of large-scale microgrid electricity transactions. The algorithm begins by utilizing a Spectral clustering algorithm to partition the blockchain network into different lower-level consensus set based on the transaction characteristics of nodes. Subsequently, a dual-layer consensus process is employed to enhance the efficiency of consensus. Additionally, we have designed a secure consensus set leader election strategy to promptly identify leaders with excellent performance. Finally, we have introduced an authentication method that combines zero-knowledge proofs and key sharing to further mitigate the risk of malicious nodes participating in the consensus. Theoretical analysis indicates that our proposed consensus algorithm, incorporating multiple layers of security measures, effectively withstands blockchain attacks such as denial of service. Simulation experiment results demonstrate that our algorithm outperforms similar blockchain algorithms significantly in terms of communication overhead, consensus latency, and throughput.
This article is a study on the use of additive obfuscation signals to keep the reference values of the agents in the continuous-time Laplacian average consensus algorithm private from eavesdroppers. Obfuscation signal...
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This article is a study on the use of additive obfuscation signals to keep the reference values of the agents in the continuous-time Laplacian average consensus algorithm private from eavesdroppers. Obfuscation signals are perturbations that agents add to their local dynamics and their transmitted-out messages to conceal their private reference values. An eavesdropper is an agent inside or outside the network that has access to some subset of the interagent communication messages, and its knowledge set also includes the network topology. Rather than focusing on using a zero-sum and vanishing additive signal, our work determines the necessary and sufficient conditions that define the set of admissible obfuscation signals that do not perturb the convergence point of the algorithm from the average of the reference values of the agents. Of theoretical interest, our results show that this class includes nonvanishing signals as well. Given this broader class of admissible obfuscation signals, we define a deterministic notion of privacy preservation. In this definition, privacy preservation for an agent means that neither the private reference value nor a finite set of values to which the private reference value of the agent belongs to can be obtained. Then, we evaluate the agents' privacy against eavesdroppers with different knowledge sets.
Supported by cloud computing, Federated Learning (FL) has experienced rapid advancement, as a promising technique to motivate clients to collaboratively train models without sharing local data. To improve the security...
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Supported by cloud computing, Federated Learning (FL) has experienced rapid advancement, as a promising technique to motivate clients to collaboratively train models without sharing local data. To improve the security and fairness of FL implementation, numerous Blockchain-empowered Federated Learning (BFL) frameworks have emerged accordingly. Among them, consensus algorithms play a pivotal role in determining the scalability, security, and consistency of BFL systems. Existing consensus solutions to block producer selection and reward allocation either focus on well-resourced scenarios or accommodate BFL based on clients' contributions to model training. However, these approaches limit consensus efficiency and undermine reward fairness, due to involving intricate consensus processes, disregarding clients' contributions during blockchain consensus, and failing to address lazy client problems (malicious clients plagiarizing local model updates from others to reap rewards). Given the aforementioned challenges, we make the first attempt to design a joint solution for efficient consensus and fair reward allocation in heterogeneous BFL systems with lazy clients. Specifically, we introduce a generalizable BFL workflow that can address lazy client problems well. Based on it, the global contribution of BFL clients is decoupled into five dominant metrics, and the block producer selection problem is formulated as a reward-constraint contribution maximization problem. By addressing this problem, the optimal block producer that maximizes global contribution can be identified to orchestrate consensus processes, and rewards are distributed to clients in proportion to their respective global contributions. To achieve it, we develop a Context-aware Proof-of-Contribution consensus algorithm named CPoC to reach consensus and incentive simultaneously, followed by theoretical analysis of lazy client problems and privacy issues. Empirical results on widely-used datasets demonstrate the ef
The growing integration of distributed generation (DG) from renewable energy sources (RES) in modern power systems highlights the need for advanced hierarchical control strategies. The primary layer is typically imple...
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The growing integration of distributed generation (DG) from renewable energy sources (RES) in modern power systems highlights the need for advanced hierarchical control strategies. The primary layer is typically implemented using a linear controller, while the secondary control relies on complex control strategies. Due to this hierarchical control AC microgrid (MG) faces unequal power sharing or power quality problems. This paper presents a hierarchical control scheme for islanded AC MG to effectively manage power between DG units. The scheme operates with a non-linear controller consisting of finite control set-voltage model predictive control (FCS-VMPC) at the primary layer and a consensus algorithm at the secondary layer. Primary control, utilizing droop control and FCS-VMPC, is independently implemented for frequency and voltage regulation across DG units. Droop control manages power distribution between DG units and loads. Meanwhile, the secondary layer based on the consensus algorithm collaborates with FCS-VMPC to establish reference voltage values and adjust deviations at the primary level. The proposed hierarchical control facilitates communication between adjacent nodes by a sparse network. This reduces the complexity of the network with FCS-VMPC at the primary and consensus algorithm at the secondary layer. The secondary controller's effectiveness is tested against transients, unbalanced loads, and dynamic load changes. The results confirm that the MG effectively supplies power while maintaining stable voltage and frequency, achieving a total harmonic distortion (THD) of 0.95 % and a maximum voltage deviation of 0.0001 pu respectively.
Aiming at the problems of low decentralization, low motivation for node voting, and malicious behavior of nodes for the traditional DPoS consensus mechanism in the blockchain-based UAV-assisted mobile edge computing e...
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Aiming at the problems of low decentralization, low motivation for node voting, and malicious behavior of nodes for the traditional DPoS consensus mechanism in the blockchain-based UAV-assisted mobile edge computing environment, this paper proposes an improved DPoS-based consensus mechanism approach. First, the framework of a blockchain-based UAV-assisted mobile edge computing system is given, and the consensus mechanism design problem in this framework is analyzed. Second, a proxy node selection model is established based on the rights and votes obtained by the blockchain nodes, and the proxy nodes are selected to participate in the consensus process of the current cycle. Then, the voting behavior, block generation behavior, and block verification behavior of nodes are classified into positive and malicious behaviors to reward and punish the reputation value of nodes. Finally, a blockchain-based UAV-assisted mobile edge computing experimental environment is built, and the TDPoS algorithm, ADRP algorithm, and RDPoS algorithm are used as benchmark algorithms to experimentally compare with the proposed improved DPoS consensus-based algorithm. The experimental results show that the algorithms in this paper can improve network throughput, reduce block-out delay, and increase the proportion of secure proxy nodes.
The financial industry faces the challenge of slow data transmission efficiency and poor security. To address these issues, a new IoT financial data transmission model based on the blockchain DPoS consensus algorithm ...
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The financial industry faces the challenge of slow data transmission efficiency and poor security. To address these issues, a new IoT financial data transmission model based on the blockchain DPoS consensus algorithm has been designed. This model introduces reputation and network nodes to enhance system stability. By evaluating and selecting reliable nodes as consensus validators, the negative impact of malicious nodes can be mitigated. Gateway nodes can act as intermediate nodes to minimise transmission delay and network congestion, while improving transmission speed and reliability. The performance test results showed that the honest nodes of the research algorithm were stable at about 91% in the 6th round of voting, while 998 valid blocks were produced at the end of 10 rounds of voting. In practical application tests, the lowest transmission rates were 2286 bps and 536 bps for different financial data sets, and the highest packet loss rates were 0.12% and 1.24%, respectively. Taken together, the above data illustrates that the research model is extremely secure and stable, and has high-data transmission efficiency and low packet loss. The research results and conclusions can provide more practical, secure and efficient solutions for data transmission problems in related fields.
The expanding use of Renewable Energy Sources (RES) has introduced a new concept of microgrids, suggested in this work as heterogeneous microgrids (HMGs). HMGs comprise single-phase and three-phase RES-based distribut...
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This paper proposes an IoT-Fog-Cloud distributed consensus algorithm for solving the energy hub(EH)dispatch problem with packet-dropping communication links and some of EH elements'*** generating and consumption u...
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This paper proposes an IoT-Fog-Cloud distributed consensus algorithm for solving the energy hub(EH)dispatch problem with packet-dropping communication links and some of EH elements'*** generating and consumption unit in this algorithm is required to estimate total power generated,total load,and power *** node coordination is accomplished using a distributed *** a distributed approach wins in work sharing,enduring a single link failure,effective decision-making,quickest convergence,and autonomy for global power *** method works with all grid types in connected and islanded *** total operation cost and emissions while meeting total demand and system constraints are the most crucial contributions of this *** case studies are applied to explain performance and effectiveness of the proposed algorithm with different packet loss *** uncertainty,sensitivity of the system was *** show mismatch between generated and consumed power is improved by 100%in the electricity grid,99.94%in heating grid,and 99.91%in gas ***,total operating cost,total emissions,and emissions cost decreased by 8.6%,13.48%,and 18.73%,respectively.
Internet of Things (IoT) devices are becoming increasingly ubiquitous in daily life. They are utilized in various sectors like healthcare, manufacturing, and transportation. The main challenges related to IoT devices ...
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Internet of Things (IoT) devices are becoming increasingly ubiquitous in daily life. They are utilized in various sectors like healthcare, manufacturing, and transportation. The main challenges related to IoT devices are the potential for faults to occur and their reliability. In classical IoT fault detection, the client device must upload raw information to the central server for the training model, which can reveal sensitive business information. Blockchain (BC) technology and a fault detection algorithm are applied to overcome these challenges. Generally, the fusion of BC technology and fault detection algorithms can give a secure and more reliable IoT ecosystem. Therefore, this study develops a new Blockchain Assisted Data Edge Verification with consensus algorithm for Machine Learning (BDEV-CAML) technique for IoT Fault Detection purposes. The presented BDEV-CAML technique integrates the benefits of blockchain, IoT, and ML models to enhance the IoT network's trustworthiness, efficacy, and security. In BC technology, IoT devices that possess a significant level of decentralized decision-making capability can attain a consensus on the efficiency of intrablock transactions. For fault detection in the IoT network, the deep directional gated recurrent unit (DBiGRU) model is used. Finally, the African vulture optimization algorithm (AVOA) technique is utilized for the optimal hyperparameter tuning of the DBiGRU model, which helps in improving the fault detection rate. A detailed set of experiments were carried out to highlight the enhanced performance of the BDEV-CAML algorithm. The comprehensive experimental results stated the improved performance of the BDEV-CAML technique over other existing models with maximum accuracy of 99.6%.
Practical Byzantine Fault Tolerance (PBFT) is one of the most important consensus algorithms in distributed systems, which can effectively respond to the threat of malicious nodes. However, PBFT still has shortcomings...
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Practical Byzantine Fault Tolerance (PBFT) is one of the most important consensus algorithms in distributed systems, which can effectively respond to the threat of malicious nodes. However, PBFT still has shortcomings in terms of arbitrary selection of primary nodes, high communication overhead, and lack of reward and punishment mechanisms. To address this problem, in this paper, we propose a comprehensive scoring-based Practical Byzantine Fault Tolerance consensus algorithm, called CS-PBFT. The algorithm introduces a comprehensive scoring mechanism to evaluate the node's reliability and overall capability, which is composed of two key metrics: node honor and recommendation scores. Based on this mechanism, the algorithm selects the primary node, slave node, and alternate node to ensure an efficient and secure consensus process. Additionally, the algorithm optimizes the communication process in the Commit and Reply phases of the PBFT consensus protocol, reducing communication latency and improving consensus efficiency. Experimental results show that the improved PBFT algorithm not only improves consensus efficiency but also reduces communication overhead, strengthens fault tolerance against malicious nodes, and demonstrates better scalability.
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