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Echoes of Disagreement: Measuring Disparity in Social consensus

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arXiv 2025年

作者： Papachristou, Marios Kleinberg, Jon Department of Computer Science Cornell University United States

Public discourse and opinions stem from multiple social groups. Each group has its own beliefs about a topic (such as vaccination, abortion, gay marriage, etc.), and opinions are exchanged and blended to produce consensus. A particular measure of interest corresponds to measuring the influence of each group on the consensus and the disparity between groups on the extent they influence the consensus. In this paper, we study and give provable algorithms for optimizing the disparity under the DeGroot or the Friedkin-Johnsen models of opinion dynamics. Our findings provide simple poly-time algorithms to optimize disparity for most cases, fully characterize the instances that optimize disparity, and show how simple interventions such as contracting vertices or adding links affect disparity. Finally, we test our developed algorithms in a variety of real-world datasets. © 2025, CC BY.

关键词： consensus algorithm

Community consensus: Converging Locally Despite Adversaries and Heterogeneous Connectivity

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Community Consensus: Converging Locally Despite Adversaries ...

American Control Conference (ACC)

作者： Cristina Gava Aron Vékássy Matthew Cavorsi Stephanie Gil Frederik Mallmann-Trenn Department of Informatics King's College London London U.K. School of Engineering Applied Sciences at Harvard University Allston MA USA

ISBN: (数字)9798350382655

ISBN: (纸本)9798350382662

We introduce the concept of community consensus in the presence of malicious agents using a well-known median-based consensus algorithm. We consider networks that have multiple well-connected regions that we term communities, characterized by specific robustness and minimum degree properties. Prior work derives conditions on properties that are necessary and sufficient for achieving global consensus in a network. This, however, requires the minimum degree of the network graph to be proportional to the number of malicious agents in the network, which is not very practical in large networks. In this work, we present a natural generalization of this previous result. We characterize cases where, although global consensus is not reached, some subsets of agents $V_{i}$ will still converge to the same values $\mathcal{M}_{i}$ among themselves. To reach this new type of consensus, we define more relaxed requirements in terms of the number of malicious agents in each community, and the number $k$ of edges connecting an agent in a community to agents external to the community.

关键词： consensus algorithm Robustness

KR-PBFT: A Secure and Efficient consensus Mechanism for Web 3.0

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KR-PBFT: A Secure and Efficient Consensus Mechanism for Web ...

International Symposium on Parallel and Distributed Processing with Applications, ISPA

作者： Yi Zhao Qi An Meiju Yu Rula Sa Jin Zhang Computer Science Inner Mongolia University Hohhot China

ISBN: (数字)9798331509712

ISBN: (纸本)9798331509729

Web 3.0, an integral component of the future internet, aims to offer users more diversified and engaging web services. Blockchain as a crucial technology, addresses decentralization, data security, and tamper resistance, laying the groundwork for the next generation of the internet. The blockchain consensus algorithm plays a pivotal role in supporting the infrastructure and services of Web 3.0. However, the widely adopted PBFT consensus algorithm in blockchain suffers from significant communication overhead and arbitrary selection of primary nodes, resulting in low consensus efficiency and compromised security. To address this, we propose an enhanced PBFT consensus mechanism based on the k-medoids clustering algorithm and a reputation evaluation mechanism. Initially, nodes are hierarchically clustered based on location features using the improved K-medoids algorithm before the consensus process begins, thereby simplifying the three-phase consensus process into two- phase. Additionally, a dynamic reputation evaluation mechanism is introduced to enhance the election process of primary nodes. Experimental results demonstrate that the KR-PBFT algorithm effectively reduces communication overhead and consensus latency while maintaining a low view change frequency and certain fault tolerance, thereby ensuring system security and stability.

关键词： Semantic Web Resistance Web services Heuristic algorithms Voting Clustering algorithms consensus algorithm Throughput consensus protocol Next generation networking

Improved PBFT consensus Based on Reputation System in Vehicle Network

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Improved PBFT Consensus Based on Reputation System in Vehicl...

IEEE/ACM International Symposium on Big Data Computing (BDC)

作者： Jing Zhang Peiyv Yang Jie Cui Lu Wei Hong Zhong Anhui University HeFei China

ISBN: (数字)9798350367300

ISBN: (纸本)9798350367317

Blockchain technology is a decentralized distributed database technology, which greatly improves the security and credibility of the data exchange process through decentralization. A great deal of research has already been conducted on combining blockchain and vehicular ad-hoc networks(VANETs) applications to solve the problems of opaque user transactions, data tampering, and insufficient motivation of participating parties. However, in the large-scale VANETs, the commonly used blockchain consensus mechanism PBFT suffers from poor scalability, high communication volume, and insufficient control of node behaviour. Therefore, in this paper, an improved consensus mechanism N-PBFT is designed for the field of VANETs based on the construction of vehicle trust management system. The improved consensus mechanism N-PBFT solves the problems of node identity peering, poor scalability, and high communication volume. After experimental testing, the proposed reputation system is able to effectively manage the information of the VANETs. And the improved PBFT consensus algorithm has a significant performance improvement over the traditional PBFT, SG-PBFT and RIPPB in terms of both throughput and latency.

关键词： Scalability Data security consensus algorithm Big Data Throughput consensus protocol Peer-to-peer computing Reliability Trust management Testing

Average consensus over Directed Networks in Open Multi-Agent Systems with Acknowledgement Feedback

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arXiv 2024年

作者： Makridis, Evagoras Grammenos, Andreas Oliva, Gabriele Kalyvianaki, Evangelia Hadjicostis, Christoforos N. Charalambous, Themistoklis Department of Electrical and Computer Engineering School of Engineering University of Cyprus Aglantzia Nicosia2109 Cyprus Department of Computer Science and Technology University of Cambridge CambridgeCB2 1TN United Kingdom Department of Engineering University Campus Bio-Medico of Rome Via Alvaro del Portillo Roma21–00128 Italy

In this paper, we address the distributed average consensus problem over directed networks in open multi-agent systems (OMAS), where the stability of the network is disrupted by frequent agent arrivals and departures, leading to a time-varying average consensus target. To tackle this challenge, we introduce a novel ratio consensus algorithm (OPENRC) based on acknowledgement feedback, designed to be robust to agent arrivals and departures, as well as to unbalanced directed network topologies. We demonstrate that when all active agents execute the OPENRC algorithm, the sum of their state variables remains constant during quiescent epochs when the network remains unchanged. By assuming eventual convergence during such quiescent periods following persistent variations in system composition and size, we prove the convergence of the OPENRC algorithm using column-stochasticity and mass-preservation properties. Finally, we apply and evaluate our proposed algorithm in a simulated environment, where agents are departing from and arriving in the network to highlight its resilience against changes in the network size and topology. © 2024, CC BY.

关键词： consensus algorithm

UNIFORM-IN-TIME MEAN-FIELD LIMIT ESTIMATE FOR THE consensus-BASED OPTIMIZATION

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arXiv 2024年

作者： Huang, Hui Kouhkouh, Hicham University of Graz Department of Mathematics and Scientific Computing NAWI Graz Graz Austria

We establish a uniform-in-time estimate for the mean-field convergence of the consensus-Based Optimization (CBO) algorithm by rescaling the consensus point in the dynamics with a small parameter κ ∈ (0,1). This uniform-in-time estimate is essential, as CBO convergence relies on a sufficiently large time horizon and is crucial for ensuring stable, reliable long-term convergence, the latter being key to the practical effectiveness of CBO *** Codes 65C35, 90C26, 90C56 © 2024, CC BY.

关键词： consensus algorithm

Balancing Security, Scalability and Decentralization of Blockchain using SHBF-Based consensus

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Balancing Security, Scalability and Decentralization of Bloc...

International Conference on Electrical Engineering and Information & Communication Technology (ICEEICT)

作者： Koli Rani Pal Jannateen Tajree Faiza Golam Ali G. M. Abdullah Al-Kafi Saha Reno Department of CSE Bangladesh Army International University of Science and Technology Cumilla Bangladesh Department of CSE Ahsanullah University of Science and Technology Dhaka Bangladesh

ISBN: (数字)9798350385779

ISBN: (纸本)9798350385786

In the dynamic realm of blockchain consensus algorithms, existing methodologies face challenges concerning security, efficiency, and adaptability. This research addresses these challenges by introducing a new consensus algorithm aimed at resolving the blockchain trilemma, achieving a balanced interplay between decentralization, security, and scalability. This consensus, which is implemented as a federated Byzantine agreement system, integrates the most effective characteristics of several consensus models, such as Proof of Authority, Honey Badger BFT, Stellar consensus, and Practical Byzantine Fault Tolerance. By integrating adaptive validation mechanisms, the algorithm incorporates the demands of both private and public blockchain ecosystems, enhancing its versatility. Through a robust fault tolerance and identity management system, this consensus ensures resilience against malicious actors, fostering a secure and dependable consensus mechanism. Furthermore, the proposed consensus algorithm optimizes time efficiency by streamlining the consensus process, drawing insights from the nomination and ballot protocol of Stellar consensus. The evaluation results indicate the proficiency of this consensus mechanism in processing transactions, achieving a rate of 1627 TPS. It notably diminishes the necessary block confirmation time to secure a 90.9% defense against double-spending while keeping the likelihood of forking at a minimal 10%. Furthermore, it attains a decentralization metric of 8.094 on a scale of 10.

关键词： Measurement Fault tolerance Scalability Heuristic algorithms Fault tolerant systems consensus algorithm consensus protocol

Differentially Private consensus Under Quantized Communication with Dynamic Event-Triggered Mechanism

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Differentially Private Consensus Under Quantized Communicati...

Chinese Automation Congress (CAC)

作者： Danzhe Liu Lijuan Zha Jinliang Liu College of Information Engineering Nanjing University of Finance and Economics Nanjing China College of Science Nanjing Forestry University Nanjing China School of Computer Science Nanjing University of Information Science and Technology Nanjing China

ISBN: (数字)9798350368604

ISBN: (纸本)9798350368611

This study delves into the differentially private consensus problem in multi-agent systems (MASs), leveraging a dynamic event-triggered (DET) mechanism to ensure privacy-preserving consensus under a quantized communication setting. We develop a consensus algorithm for differential privacy communication that employs a uniform quantizer. This approach safeguards the agent's initial or present state against information leaks by relaying quantized data. To reduce the frequency of controller updates, a DET protocol, which is based on an auxiliary variable and local estimations, is implemented to control the data transmission. Subsequently, necessary criteria are established to guarantee mean square consensus performance when an unbounded quantizer is used. In conclusion, simulation examples are included to validate the results obtained.

关键词： Differential privacy Protocols Event detection Simulation Estimation consensus algorithm Frequency estimation Data communication Frequency control Multi-agent systems

Parallel algorithms for Median consensus Clustering in Complex Networks

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arXiv 2024年

作者： Hussain, Md Taufique Halappanavar, Mahantesh Chatterjee, Samrat Radicchi, Filippo Fortunato, Santo Azad, Ariful Department of Intelligent Systems Engineering Indiana University BloomingtonIN United States Data Sciences and Machine Intelligence Group Pacific Northwest National Laboratory RichlandWA United States Indiana University BloomingtonIN United States

We develop an algorithm that finds the consensus of many different clustering solutions of a graph. We formulate the problem as a median set partitioning problem and propose a greedy optimization technique. Unlike other approaches that find median set partitions, our algorithm takes graph structure into account and finds a comparable quality solution much faster than the other approaches. For graphs with known communities, our consensus partition captures the actual community structure more accurately than alternative approaches. To make it applicable to large graphs, we remove sequential dependencies from our algorithm and design a parallel algorithm. Our parallel algorithm achieves 35x speedup when utilizing 64 processing cores for large real-world graphs from single-cell experiments. © 2024, CC BY.

关键词： consensus algorithm