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As a resource-friendly consensus protocol, Proof-of-Authority (PoA) has been widely deployed in IoT applications with blockchain technology. It relies on a fixed set of trusted nodes called validators for block generation. In contrast to traditional consensus mechanisms, PoA offers better performance but also leads to a centralized blockchain. In a centralized blockchain, PoA gives a few authorities the power to tamper with all nodes. To improve the decentralization of the protocol, this paper proposes a proof of authority based on a dynamic set of validators (DyPoA). The protocol decouples the right to generate and commit blocks to the blockchain from the authority node in the original PoA. It enables unauthenticated nodes to perform the process of packing transactions into blocks, while authenticated nodes validate and commit blocks to the blockchain. Additionally, DyPoA introduces a contribution score mechanism to measure the work accomplished by each node when a block is appended to the blockchain. Based on the contribution score, DyPoA selects and replaces validators through cryptographic sortition. We evaluate DyPoA through decentralization metrics and performance tests. The experimental results show that the Shannon entropy, Gini coefficient, and Nakamoto coefficient of DyPoA are 1.5 times, 0.7 times, and 1.7 times that of the original PoA, respectively, and achieve a 2.2x throughput improvement and 3x latency reduction compared to the original PoA. [ABSTRACT FROM AUTHOR]

The circulation of digital assets has become increasingly crucial in today's digital economy, reflecting both its growing importance and the challenges it faces. Blockchain technology, with its inherent symmetry, has emerged as a transformative force in facilitating digital asset circulation, addressing various issues related to security, efficiency, and transparency. This paper aims to advance the development of digital asset circulation technologies by focusing on four key blockchain-based technologies: smart contracts, consensus algorithms, cross-chain technology, and decentralized exchanges. These technologies embody symmetry in their structure and operation, ensuring balanced and secure asset management across decentralized networks. This paper reviews the evolution of these key technologies, highlighting their contributions to the digital asset ecosystem. It explores effective application cases and analyzes the current challenges each technology faces. Additionally, this paper provides insights into potential future developments and directions to address these challenges and enhance the overall efficiency and reliability of digital asset circulation. [ABSTRACT FROM AUTHOR]

Blockchain technology, with its decentralized nature, offers a more secure, reliable, and transparent solution for the Internet of Things (IoT). However, directly deploying existing consensus protocols in many IoT environments can limit scalability, lead to high computational costs and delays, and fail to meet the high responsiveness required for network communication. Additionally, IoT devices vary widely in performance, and lower-performance devices participating as nodes in a decentralized network may not be able to meet the demands of the consensus process, resulting in consensus delays and decreased system stability. This proposal introduces an improved consensus protocol called Ghost-Weight, based on the original Ghost protocol, designed to accommodate the performance-heterogeneous IoT environment with frequent information exchanges. Ghost-Weight introduces the concept of a Dominant Block, which, through a mechanism called the Confinement Edge, incorporates forked blocks within the network in a graph-based manner. The ForkBlock Process then organizes these blocks, removes conflicting transactions, and ultimately achieves global consensus based on weight before publishing them to the network. Furthermore, the protocol proposes a node partitioning strategy, ensuring that devices of all performance levels can participate in the consensus process. Through experiments and theoretical comparisons, we demonstrate that this protocol achieves a 52% increase in throughput, a 23% improvement in transaction confirmation time, and a 56% higher efficiency in processing forked blocks compared to the original Ghost protocol. We also designed a series of experiments to showcase Ghost-Weight’s success in resisting selfish mining attacks and balancing attacks. This proposal effectively addresses the challenge of deploying consensus mechanisms in performance-heterogeneous IoT environments with high responsiveness requirements. Compared to previous designs, it significantly improves network scalability, transaction speed, network efficiency, and overall reliability. [ABSTRACT FROM AUTHOR]

Abstract Blockchain technology has gained attention in recent times owing to its ability to revolutionize traditional trade through its distributed ledger attribute. The prompt advancement of blockchain demands new systematic studies to investigate and analyze the existing knowledge in this domain. In the current work, the present standing and emerging trends of blockchain have been analyzed to direct both new and experienced researchers in establishing a baseline for future research projects. Likewise, the research advancement of consensus protocol was reviewed with a particular emphasis on their security perspective. Accordingly, the attributes, appropriate scenarios, and probable weaknesses of different consensus protocols and their future trends were reviewed. This helps in scrutinizing how blockchain technology can be applied to a variety of emerging fields, including economics, healthcare, information systems, wireless networks, and smart grids. Additionally, the current evaluation provides a throughout discussion of blockchain applications in various fields. Finally, the paper offers a brief insight into limitations and prospective future development in this domain. Overall, the aim is to aid newbies in investigating and scheming new solutions while considering the present demands and issues.

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.)

Research into blockchain technology has expanded significantly due to its potential to enhance transparency and trust in business operations, yet adoption is limited by technical challenges like scalability, consensus mechanisms, and security, as well as non-technical barriers such as governance and standardization. This study synthesizes findings from 21 systematic literature reviews (SLR) published between January 2009 and January 2024, focusing on the technical performance of blockchain and its integration with technologies like cloud computing and machine learning. The analysis highlights advancements in scalability, security, privacy, and smart contracts alongside areas needing more research, such as interoperability and integration with legacy systems. This comprehensive review aims to map current technological developments, identify ongoing limitations, and identify specific technical challenges that impede broader adoption. The findings direct future research towards overcoming these barriers, facilitating the smoother implementation of blockchain across various business sectors. [ABSTRACT FROM AUTHOR]

Blockchain technology has gained attention in recent times owing to its ability to revolutionize traditional trade through its distributed ledger attribute. The prompt advancement of blockchain demands new systematic studies to investigate and analyze the existing knowledge in this domain. In the current work, the present standing and emerging trends of blockchain have been analyzed to direct both new and experienced researchers in establishing a baseline for future research projects. Likewise, the research advancement of consensus protocol was reviewed with a particular emphasis on their security perspective. Accordingly, the attributes, appropriate scenarios, and probable weaknesses of different consensus protocols and their future trends were reviewed. This helps in scrutinizing how blockchain technology can be applied to a variety of emerging fields, including economics, healthcare, information systems, wireless networks, and smart grids. Additionally, the current evaluation provides a throughout discussion of blockchain applications in various fields. Finally, the paper offers a brief insight into limitations and prospective future development in this domain. Overall, the aim is to aid newbies in investigating and scheming new solutions while considering the present demands and issues. [ABSTRACT FROM AUTHOR]

IoT data exchange services are emerging to connect various and distributed IoT data sources, which facilitate data owners exchange their IoT data flexibly. Traditional IoT data exchange services rely on a centralized third-party to negotiate the settlement of trades between data consumers and providers. Such settlement model suffers from issues including single point of failure, extra settlement fee, un-transparency of settlement details, to name a few. New settlement model is imperative to overcome such limitations. Blockchain is an innovative technology that is competent in governing the decentralized network, which poses great opportunity to implement fair settlement in decentralized manner. In this paper, we propose a Blockchain-enabled settlement model for decentralized IoT data exchange services. Firstly, Bitcoin-based time commitment scheme is adopted to build fair and autonomous settlement model. Furthermore, to enhance the accountability of all transactions, an optimized practical Byzantine fault tolerant consensus protocol named ReBFT, is proposed to enable all members involved in the IoT data exchange application achieve identical shared ledger recording all transactions. Finally, experiments are conducted to verify the feasibility of our proposal. [ABSTRACT FROM AUTHOR]

This paper proposes a linear consensus protocol QuickBFT based on Vague sets and multi-attribute decision-making methods. QuickBFT simplifies the communication process based on the HotStuff protocol, reduces the four-stage communication to three-stage communication, and reduces the consensus delay. Furthermore, we introduce the Vague set and multi-attribute decision-making theory into the consensus protocol and propose a new leader node selection algorithm, which can prevent Byzantine nodes from becoming leader nodes, thereby improving the protocol performance when the leader node is attacked. Experimental results show that the throughput of QuickBFT is slightly higher than that of the HotStuff protocol without Byzantine nodes, and the consensus delay is reduced by 20%. In the presence of Byzantine nodes, the throughput of QuickBFT is increased by 80% compared with the HotStuff protocol, and the consensus delay is reduced by 60%. [ABSTRACT FROM AUTHOR]

Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores 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.)

Consensus protocols, as crucial components of blockchain technology, play a vital role in ensuring data consistency among distributed nodes. However, the existing voting-based and proof-based consensus protocols encounter scalability issues within the blockchain system. Moreover, most consensus protocols are serialized, which further limits their scalability potential. To address this limitation, parallelization methods have been employed in both types of consensus protocols. Surprisingly, however, novel fusion consensus protocols demonstrate superior scalability compared with these two types but lack the utilization of parallelization techniques. In this paper, we present PnV, an efficient parallel fusion protocol integrating proof-based and voting-based consensus features. It enhances the data structure, consensus process, transaction allocation, and timeout handling mechanisms to enable concurrent block generation by multiple nodes within a consensus round. Experimental results demonstrate that PnV exhibits superior efficiency, excellent scalability, and acceptable delay compared with Proof of Vote (PoV) and BFT-SMART. Moreover, at the system level, the performance of the PnV-based blockchain system optimally surpasses that of the FISCO BCOS platform. Our proposed protocol contributes to advancing blockchain technology by providing a more efficient and practical solution for achieving decentralized consensus in distributed systems. [ABSTRACT FROM AUTHOR]

Background and purpose: Treatment planning for MR-guided stereotactic body radiotherapy (SBRT) for pancreatic tumors can be challenging, leading to a wide variation of protocols and practices. This study aimed to harmonize treatment planning by developing a consensus planning protocol for MR-guided pancreas SBRT on a 1.5 T MR-Linac. Materials and methods: A consortium was founded of thirteen centers that treat pancreatic tumors on a 1.5 T MR-Linac. A phased planning exercise was conducted in which centers iteratively created treatment plans for two cases of pancreatic cancer. Each phase was followed by a meeting where the instructions for the next phase were determined. After three phases, a consensus protocol was reached. Results: In the benchmarking phase (phase I), substantial variation between the SBRT protocols became apparent (for example, the gross tumor volume (GTV) D99% ranged between 36.8 – 53.7 Gy for case 1, 22.6 – 35.5 Gy for case 2). The next phase involved planning according to the same basic dosimetric objectives, constraints, and planning margins (phase II), which led to a large degree of harmonization (GTV D99% range: 47.9–53.6 Gy for case 1, 33.9–36.6 Gy for case 2). In phase III, the final consensus protocol was formulated in a treatment planning system template and again used for treatment planning. This not only resulted in further dosimetric harmonization (GTV D99% range: 48.2–50.9 Gy for case 1, 33.5–36.0 Gy for case 2) but also in less variation of estimated treatment delivery times. Conclusion: A global consensus protocol has been developed for treatment planning for MR-guided pancreatic SBRT on a 1.5 T MR-Linac. Aside from harmonizing the large variation in the current clinical practice, this protocol can provide a starting point for centers that are planning to treat pancreatic tumors on MR-Linac systems.

For decentralized characteristics of blockchain platforms, Byzantine Fault Tolerance (BFT) consensus protocols have been widely used to reach an agreement among nodes in the presence of malicious node attacks. However, due to their communication complexity, BFT consensus protocols are considered one major cause of the limited scalability of a blockchain platform. In this study, we propose two performance improvement techniques — Pipelining and Overlapping — to simplify the BFT consensus protocol without sacrificing decentralization. These techniques are designed to concurrently optimize throughput and minimize latency, irrespective of an increase or broad dispersion in consensus node deployment. We demonstrate the efficacy of these techniques through their application to AuditChain, a private blockchain leveraging a PBFT-like consensus mechanism with linear communication complexity. In a WAN environment utilizing AWS EC2 with 4 consensus nodes deployed in one region (ap-northeast-2), the system achieves about 1997 tx/s with a latency of 0.1 seconds. By further enhancing the distribution characteristics of our experimental environment, even with 32 consensus nodes distributed across two regions (ap-northeast-2, us-east-1), the system still achieves about 1995 tx/s with a latency of 0.3 seconds. These findings suggest that the proposed techniques are capable of significantly improving the performance metrics of BFT-based blockchain systems.

The circulation of digital assets has become increasingly crucial in today’s digital economy, reflecting both its growing importance and the challenges it faces. Blockchain technology, with its inherent symmetry, has emerged as a transformative force in facilitating digital asset circulation, addressing various issues related to security, efficiency, and transparency. This paper aims to advance the development of digital asset circulation technologies by focusing on four key blockchain-based technologies: smart contracts, consensus algorithms, cross-chain technology, and decentralized exchanges. These technologies embody symmetry in their structure and operation, ensuring balanced and secure asset management across decentralized networks. This paper reviews the evolution of these key technologies, highlighting their contributions to the digital asset ecosystem. It explores effective application cases and analyzes the current challenges each technology faces. Additionally, this paper provides insights into potential future developments and directions to address these challenges and enhance the overall efficiency and reliability of digital asset circulation.

Blockchain technology is a decentralized and secure paradigm for data processing, sharing, and storing. It relies on consensus protocol for all decisions, which focuses on computational and resource capability. For example, proof of work (PoW) and proof of stake (PoS) are the most famous consensus protocols that are currently used. However, these current consensus protocols are required to recruit a node with a high computational or a large amount of cryptocurrency to act as a miner node and to generate a new block. Unfortunately, these PoW and PoS protocols could be impractical for adoption in today's technological fields, such as the Internet of Things and healthcare. In addition, these protocols are susceptible to flexibility, security, and fairness issues, as they are discussed in detail in this work. Therefore, this paper introduces a proof of fairness (PoF) as a dynamic and secure consensus protocol for enhancing the mining selection process. The selection of the miner node is influenced by numerous factors, including the time required to generate a block based on the transaction's sensitivity. Firstly, a reverse auction mechanism is designed as an incentive mechanism to encourage all nodes to participate in the miner selection process. In a reverse auction, each node will draw its strategy based on its computational capability and claimed cost. Secondly, an expressive language is developed to categorize transaction types based on their sensitivity to processing time, ensuring compatibility with our miner selection process. Thirdly, a homomorphic concept is designed as a security and privacy scheme to protect the bidder's data confidentiality. Finally, an extensive evaluation involving numerical analysis was carried out to assess the efficiency of the suggested PoF protocol, which confirms that the proposed PoF is dynamic and more efficient than current PoW and PoS consensus protocols. [ABSTRACT FROM AUTHOR]

This study presents a distributed adaptive sliding mode consensus protocol (DASMCP) to solve the consensus problem of the high‐order heterogeneous closed‐loop nonlinear uncertainty multi‐agent system without prior knowledge. The proposed adaptive gains adjustment mechanism can decrease the states and input chattering. In addition, the DASMCP is independent of prior knowledge of communication topology and error dynamics, and its finite time convergence bound can be preset. Moreover, two simulation examples are shown to verify the performance and the engineering application scenario. [ABSTRACT FROM AUTHOR]

Traditional central control system is unable to deal with the optimal control tasks of modern distribution networks due to its low reliability, high computation and communication burden and poor expansibility. Based on distributed collaboration principle, this paper presents a multiple-object distributed optimisation control strategy for distribution network utilising DG grouping method. Distributed control strategy for node voltage control group is developed by taking the capacity utilisation ratio (CUR) of DG as the consensus variable, to comply with the feature of high resistance/reactance ratio of distribution network feeder line. Distributed control strategies for exchanged power control groups, which respectively takes CUR and power factor as the consensus variable, are formulated according to the different conditions of exchanged power imbalance. The parameter tuning method for three kinds of distributed optimisation control strategies are presented. The correctness and effectiveness of the proposed method are verified by simulation examples in the IEEE 14-node system, and simulation results on the IEEE 33-node test system are presented to show the robustness of the method to the disturbances related with distributed generation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics 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.)

Research into blockchain technology has expanded significantly due to its potential to enhance transparency and trust in business operations, yet adoption is limited by technical challenges like scalability, consensus mechanisms, and security, as well as non-technical barriers such as governance and standardization. This study synthesizes findings from 21 systematic literature reviews (SLR) published between January 2009 and January 2024, focusing on the technical performance of blockchain and its integration with technologies like cloud computing and machine learning. The analysis highlights advancements in scalability, security, privacy, and smart contracts alongside areas needing more research, such as interoperability and integration with legacy systems. This comprehensive review aims to map current technological developments, identify ongoing limitations, and identify specific technical challenges that impede broader adoption. The findings direct future research towards overcoming these barriers, facilitating the smoother implementation of blockchain across various business sectors.

In this paper, an adaptive distributed formation controller for wheeled nonholonomic mobile robots is developed. The dynamical model of the robots is first derived by employing the Euler-Lagrange equation while taking into consideration the presence of disturbances and uncertainties in practical applications. Then, by incorporating fractional calculus in conjunction with fast terminal sliding mode control and consensus protocol, a robust distributed formation controller is designed to assure a fast and finite-time convergence of the robots towards the required formation pattern. Additionally, an adaptive mechanism is integrated to effectively counteract the effects of disturbances and uncertain dynamics. Moreover, the suggested control scheme's stability is theoretically proven through the Lyapunov theorem. Finally, simulation outcomes are given in order to show the enhanced performance and efficiency of the suggested control technique. [ABSTRACT FROM AUTHOR]

The consensus protocol is one of the core technologies in blockchain, which plays a crucial role in ensuring the block generation rate, consistency, and safety of the blockchain system. Blockchain systems mainly adopt the Byzantine Fault Tolerance (BFT) protocol, which often suffers from slow consensus speed and high communication consumption to prevent Byzantine nodes from disrupting the consensus. In this paper, this paper proposes a new dual-mode consensus protocol based on node identity authentication. It divides the consensus process into two subprotocols: Check_BFT and Fast_BFT. In Check_BFT, the replicas authenticate the primary's identity by monitoring its behaviors. First, assume that the systemis in a pessimistic environment, Check_BFT protocol detects whether the current environment is safe and whether the primary is an honest node; Enter the fast consensus stage after confirming the environmental safety, and implement Fast_BFT protocol. It is assumed that there are 3f + 1 nodes in total. If more than 2f + 1 nodes identify that the primary is honest, it will enter the Fast_BFT process. In Fast_BFT, the primary is allowed to handle transactions alone, and the replicas can only receive the messages sent by the primary. The experimental results show that the CF-BFT protocol significantly reduces the communication overhead and improves the throughput and scalability of the consensus protocol. Compared with the SAZyzz protocol, the throughput is increased by 3 times in the best case and 60%in the worst case. [ABSTRACT FROM AUTHOR]

Abstract Since its inception, bitcoin has used the popular consensus protocol proof-of-work (PoW). PoW has a well-known flaw: it distributes all rewards to a single miner (or pool) who inserts a new block. Consequently, the variance of rewards and the mining enterprise risk are extremely high. In 2016, Shi proposed addressing this problem with a theoretical algorithm. We introduce an easily-implemented PoW variant that improves Shi’s idea. The network must not find a single nonce but a few to insert a block. This simple change allows for a fairer distribution of rewards and also has the effect of regularizing the insertion time of blocks. This method would facilitate the emergence of small pools or autonomous miners.

Consensus protocols, as crucial components of blockchain technology, play a vital role in ensuring data consistency among distributed nodes. However, the existing voting-based and proof-based consensus protocols encounter scalability issues within the blockchain system. Moreover, most consensus protocols are serialized, which further limits their scalability potential. To address this limitation, parallelization methods have been employed in both types of consensus protocols. Surprisingly, however, novel fusion consensus protocols demonstrate superior scalability compared with these two types but lack the utilization of parallelization techniques. In this paper, we present PnV, an efficient parallel fusion protocol integrating proof-based and voting-based consensus features. It enhances the data structure, consensus process, transaction allocation, and timeout handling mechanisms to enable concurrent block generation by multiple nodes within a consensus round. Experimental results demonstrate that PnV exhibits superior efficiency, excellent scalability, and acceptable delay compared with Proof of Vote (PoV) and BFT-SMART. Moreover, at the system level, the performance of the PnV-based blockchain system optimally surpasses that of the FISCO BCOS platform. Our proposed protocol contributes to advancing blockchain technology by providing a more efficient and practical solution for achieving decentralized consensus in distributed systems.

The modern pharmaceutical supply chain lacks transparency and traceability, resulting in alarming rates of counterfeit products entering the market. These illegitimate products cause harm to end users and wreak havoc on the supply chain itself, costing billions of dollars in profit loss. In this paper, in response to the Drug Supply Chain Security Act (DSCSA), we introduce Janus, a novel pharmaceutical track-and-trace system that utilizes blockchain and cloning-resistant hologram tags to prevent counterfeits from entering the pharmaceutical supply chain. We design a multi-quorum consensus protocol that achieves load balancing across the network. We perform a security analysis to show robustness against various threats and attacks. The implementation of Janus proves that the system is fair, scalable, and resilient.

Accommodating an increasing number of users in the Blockchain network has moved to the forefront of discussion. It is also evident that without jeopardizing the data security in Blockchain, it is of indispensable need to devise an appropriate method for improving the scalability trait of Blockchain. In this article, we have proposed a consensus method that is having the potential to improve the scalability of the Private Blockchain. The system, at first, mitigates latency arising from kernel schedulers, ensuring that the application consistently has access to an available core for transaction processing. Secondly, the committee system alleviates the network's workload, preventing spurious transactions from monopolizing network resources and impeding its efficiency. Extensive experimentation is made by considering various scenarios of transaction with CPU isolation and application sticking to core 2 with varied priority. Based on the number of transactions performed per second, the proposed system is compared with different existing consensus mechanisms working in various types of Blockchains. Also, a detailed discussion is presented on the critical analysis of the adopted research mechanism. Overall, the proposed systems outperforms to other systems in various parameters of blockchain network scalability.

E-coupons have gradually gained attention with the development of the e-commerce market. The traditional e-coupon system is based on a centralized organization with problems, such as a single point of failure and e-coupon counterfeiting. Blockchain possesses characteristics such as decentralization that can enhance traditional e-coupon systems. In this study, we designed an e-coupon system based on blockchain called Ecoupon-Chain. First, we defined the mini-block, designed the account, block, and transaction structure, and built the system model. Second, we proposed a simple and efficient consensus protocol called Proof of Activeness to improve the system’s throughput and encourage nodes to perform transactions. Finally, we built a prototype of this e-coupon system and conducted security analysis and experimental evaluation on the prototype. The results show that the system can resist typical attacks, such as fork, double spending, replay, and Sybil attacks. The system throughput can be maintained above 1000 transactions per second under specific circumstances. The efficiency of the system is significantly improved compared to that of the existing consensus protocol. We present a simplified prototype of Ecoupon-Chain at https://github.com/YangYi215613/Ecoupon-Chain.

With the advent of the digital age, traditional lifestyle activities, such as reading books, referencing recipes, and enjoying music, have progressively transitioned from offline to online. However, numerous issues plague the conventional approach to digital copyright protection. This is especially true in the realm of recipe protection, where the rights and interests of original creators are inadequately safeguarded due to the widespread dissemination of a large number of recipes on the Internet. This primarily stems from the high costs of gathering evidence, incomplete coverage of evidence collection, and the inability to identify and halt infringement activities in a timely manner during the process of traditional digital copyright protection. Therefore, this study designs and implements a blockchain-based digital recipe copyright protection scheme to address the issues of insufficient legal evidence and cumbersome processes in traditional digital copyright protection. First, we enhance standard short text similarity calculation method SimHash, boosting the accuracy of text similarity detection. We then utilize the decentralization, immutability, time-stamping, traceability, and smart contract features of blockchain technology for data privacy protection. We employ the Interplanetary File System (IPFS) to store raw data, thereby ensuring user privacy and security. Lastly, we improve the proxy voting node selection in the existing delegated proof of stake (DPOS) consensus mechanism. According thorough evaluation and empirical analysis, the scheme effectively improves the accuracy of text similarity detection. Simultaneously, the enhanced DPOS mechanism effectively rewards nodes with excellent performance and penalizes nodes exhibiting malicious behavior. In this study, we successfully designed and implemented an innovative digital recipe copyright protection scheme. This scheme effectively enhances the accuracy of text similarity detection; ensures the privacy and security of user data; and, through an enhanced DPOS mechanism, rewards well-performing nodes while penalizing those exhibiting malicious behavior. [ABSTRACT FROM AUTHOR]

The blockchain has gained widespread attention due to its decentralized, secure, traceable, and immutable characteristics. However, current consensus protocols face the challenge of limited scalability and inadequate consideration of dynamic node behavior in large-scale networks. They cannot effectively adapt to the increasing number of nodes and the subsequent network traffic surge. Furthermore, their inability to sufficiently address dynamic node behavior poses a risk to the consensus process and compromises the overall reliability of the system. A cluster reputation-based hierarchical consensus model (CRHCM) has been proposed to addresses node dynamics and improves network scalability in this paper. The model introduces a reputation system that updates node reputations based on both current and historical behaviors during the consensus process. Node reputation fluctuations are assessed using a discrete Markov chain, which enables the identification of abnormal nodes and improves overall node reliability. Furthermore, a hierarchical structure has been proposed to improve scalability and reduce the communication complexity of blockchain by assigning nodes to the upper or lower layers through reputation and fluctuation levels. Experimental and theoretical evaluations demonstrate the effectiveness of CRHCM. The model achieves a balanced distribution of reputation values among all nodes and exhibits high scalability. It has excellent performance by comparisons with some other state-of-the-arts. [ABSTRACT FROM AUTHOR]

Motivated from the mean‐square bounded consensus (MSBD) problem of multiagent systems (MASs) with additive noise, this paper studies the joint influence of the agent dynamic structure and communication topology on the consensus. The necessary condition of MSBD is given under the output‐based consensus protocol, which is also sufficient under some mild conditions. Furthermore, the upper consensus bound is given via the solution of the Lyapunov equation. Finally, simulation results are provided to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

With the increasing growth rate of smart home devices and their interconnectivity via the Internet of Things (IoT), security threats to the communication network have become a concern. This paper proposes a learning engine for a smart home communication network that utilizes blockchain-based secure communication and a cloud-based data evaluation layer to segregate and rank data on the basis of three broad categories of Transactions (T), namely Smart T, Mod T, and Avoid T. The learning engine utilizes a neural network for the training and classification of the categories that helps the blockchain layer with improvisation in the decision-making process. The contributions of this paper include the application of a secure blockchain layer for user authentication and the generation of a ledger for the communication network; the utilization of the cloud-based data evaluation layer; the enhancement of an SI-based algorithm for training; and the utilization of a neural engine for the precise training and classification of categories. The proposed algorithm outperformed the Fused Real-Time Sequential Deep Extreme Learning Machine (RTS-DELM) system, the data fusion technique, and artificial intelligence Internet of Things technology in providing electronic information engineering and analyzing optimization schemes in terms of the computation complexity, false authentication rate, and qualitative parameters with a lower average computation complexity; in addition, it ensures a secure, efficient smart home communication network to enhance the lifestyle of human beings. [ABSTRACT FROM AUTHOR]

A Blockchain network consists of a distributed ledger and a set of nodes participating in the network. The consistency in the ledger’s state is maintained by a Blockchain consensus mechanism. This property is essential since it is assumed that the participants in the network do not trust each other. Most Blockchain consensus algorithms are unsuitable for resource-constrained nodes due to their power consumption, storage, network overhead, and computation requirements. Furthermore, many consensus methods do not address the issue of data accountability, which guarantees that an entity will be judged on its performance or conduct concerning a duty they have taken. This study proposes a novel consensus mechanism termed Proof of Block Height (PoBH) that prioritizes accountability for reporting IoT data transactions and considers factors such as low computation cost and energy consumption. The approach relies on a pre-existing comparable deterministic value based on the height of the committed blocks. The model identifies a malicious intent using a set of predicates and consequently incurs a computation penalty to keep such nodes away from the network. As a preventive measure, the model also seeks to increment this penalty appropriately by making the network free from dishonest nodes for as long as possible, thus sanitizing the network. Importantly, the developed method does not augment the basic hierarchy of an IoT network. A formal analysis of the mechanism’s operation shows that the resource and time required to cheat the system grows exponentially with the number of faulty blocks a node tries to append to the shared ledger. The factors affecting the mechanism’s performance, scalability, and effort required (by malicious nodes) to stay within the network are also quantitatively evaluated. [ABSTRACT FROM AUTHOR]

Despite the widespread clinical use of dynamic susceptibility contrast (DSC) MRI, DSC-MRI methodology has not been standardized, hindering its utilization for response assessment in multicenter trials. Recently, the DSC-MRI Standardization Subcommittee of the Jumpstarting Brain Tumor Drug Development Coalition issued an updated consensus DSC-MRI protocol compatible with the standardized brain tumor imaging protocol (BTIP) for high-grade gliomas that is increasingly used in the clinical setting and is the default MRI protocol for the National Clinical Trials Network. After reviewing the basis for controversy over DSC-MRI protocols, this paper provides evidence-based best practices for clinical DSC-MRI as determined by the Committee, including pulse sequence (gradient echo vs spin echo), BTIP-compliant contrast agent dosing (preload and bolus), flip angle (FA), echo time (TE), and post-processing leakage correction. In summary, full-dose preload, full-dose bolus dosing using intermediate (60°) FA and field strength-dependent TE (40-50 ms at 1.5 T, 20-35 ms at 3 T) provides overall best accuracy and precision for cerebral blood volume estimates. When single-dose contrast agent usage is desired, no-preload, full-dose bolus dosing using low FA (30°) and field strength-dependent TE provides excellent performance, with reduced contrast agent usage and elimination of potential systematic errors introduced by variations in preload dose and incubation time.

In this work, we propose a satellite-aided permissionless consensus protocol for scalable space-terrestrial blockchains. We design its working principle and workflow by taking full advantage of satellites for extensive coverage and ubiquitous connectivity. Based on the proposed protocol, we demonstrate how such a space-terrestrial blockchain grows and evolves through several typical cases in the presence of adversarial nodes, user misbehavior, and transmission outage. Taking proof of work (PoW) as a benchmark, we assess the system security by considering both adversarial miners and possible colluding satellites. Then, we analyze the maximum blockchain throughput under network capacity limits and evaluate the impact of information propagation delay via a Markov model. Simulation results support that the proposed satellite-aided consensus protocol achieves higher throughput and exhibits greater scalability than PoW.

Current consensus protocols for permissionless blockchain cannot balance security, performance and centralization issues. In the paper, we present a reputation based consensus, FPoR, which combines reputation, committee based consensus, PBFT, reward and penalization mechanisms. FPoR can balance scalability, security and decentralization, and promote fairness, increase participation and strengthen security. Experiment results show that FPoR is with high performance and scalability, which can be used for permissionless blockchain. FPoR can also be extended to permissioned blockchain applications.

Consensus protocol has challenges in terms of low consensus efficiency and centralization, as well as poor fault tolerance. A joint reputation model based grouping and hierarchical byzantine fault tolerance consensus protocol has been proposed. It is composed of both grouping and hierarchical models. The grouping model uses joint reputation values to balance node grouping, minimize overall differences in joint reputation values among groups. Some nodes with a joint reputation value ranking in the top 50% of the group are randomly selected as function ones, which improves the degree of decentralization compared to some election strategies of leader nodes. In the hierarchical model, nodes in each group are layered and the supervision nodes are mapped to the upper layer, which improves consensus network security and efficiency. Besides a new communication structure has been designed to improve fault tolerance and reduce communication complexity by improving the three phases of Practical Byzantine Fault Tolerant (PBFT). Comparative experiments have shown the superiority of the developed protocol over other existing protocols.