Block Verification Research Articles

A quantitative analysis of the security of PoW-based blockchains

This study analyzes the security implications of Proof-of-Work blockchains with respect to the stale block rate and the lack of a block verification process. The stale block rate is a crucial security metric that quantifies the proportion of rejected blocks in the blockchain network. The absence of a block verification process represents another critical security concern, as it permits the potential for invalid transactions within the network. In this article, we propose and implement a quantitative and analytical model to capture the primary operations of Proof-of-Work blockchains utilizing the Performance Evaluation Process Algebra. The proposed model can assist blockchain designers, architects, and analysts in achieving the ideal security level for blockchain systems by determining the proper network and consensus settings. We conduct extensive experiments to determine the sensitivity of security to four aspects: the number of active miners and their mining hash rates, the duration between blocks, the latency in block propagation, and the time required for block verification, all of which have been shown to influence the outcomes. We contribute to the findings of the existing research by conducting the first analysis of how the number of miners affects the frequency of stale block results, as well as how the delay in block propagation influences the incentives received by rational miners who choose to avoid the block verification process.

A lightweight practical consensus mechanism for supply chain blockchain

We present a consensus mechanism in this paper that is designed specifically for supply chain blockchains, with a core focus on establishing trust among participating stakeholders through a novel reputation-based approach. The prevailing consensus mechanisms, initially crafted for cryptocurrency applications, prove unsuitable for the unique dynamics of supply chain systems. Unlike the broad inclusivity of cryptocurrency networks, our proposed mechanism insists on stakeholder participation rooted in process-specific quality criteria. The delineation of roles for supply chain participants within the consensus process becomes paramount. While reputation serves as a well-established quality parameter in various domains, its nuanced impact on non-cryptocurrency consensus mechanisms remains uncharted territory. Moreover, recognizing the primary role of efficient block verification in blockchain-enabled supply chains, our work introduces a comprehensive reputation model. This model strategically selects a leader node to orchestrate the entire block mining process within the consensus. Additionally, we innovate with a Schnorr Multisignature-based block verification mechanism seamlessly integrated into our proposed consensus model. Rigorous experiments are conducted to evaluate the performance and feasibility of our pioneering consensus mechanism, contributing valuable insights to the evolving landscape of blockchain technology in supply chain applications.

Focal pulsed field ablation for organised atrial tachyarrhythmias: one to rule them all

Abstract Background Focal pulsed field ablation (fPFA) has emerged as a versatile and innovative strategy for ablating atrial tachyarrhythmias (1). The primary objective of this study is to present the short-term safety characteristics, feasibility and procedural outcomes of fPFA in the management of organised atrial tachyarrhythmias. This report focuses on the commercial use of an innovative pulsed field ablation (PFA) generator, utilized in conjunction with commercially available focal, solid-tip ablation catheters, and complemented by 3D electro-anatomical mapping (3D-EAM). Methods Patients with organised atrial tachycardia treated using fPFA between August 2022 and September 2023 at our center were included in this retrospective analysis. Tachycardia mechanisms were identified with high-definition, multi-electrode mapping catheter paired with 3D-EAM system. Ablation lines, when targeting macro-reentrant arrhythmias were strategicaly positioned to adress critical isthmi when recognised or they were empirically placed between the anatomical obstacles ( including LA roof, anterior, mitral isthmus, upper septal and cavotricuspid line as deemed appropriate). Positioning of the fPFA catheter was guided by 3D-EAM, intracardiac ultrasound, and fluoroscopy (Figure 1). Bidirectional block verification was performed using standard criteria to assess acute procedural success. Glyceryl trinitrate boluses were administered prior to ablation in proximity to coronary arteries. Results In a cohort of 36 patients (median age 62 years; 12 females), we effectively mapped and treated a total of 51 distinct organised atrial tachyarrhythmias. These included 18 typical flutters, 3 roof-dependent macro-reentries, 4 posterior-wall micro-reentries, 15 peri-mitral macro-reentries, 8 anterior-wall micro-reentries and 3 biatrial macro-reentries via Bachman bundle. Our ablation strategy involved creating 21 cavotricuspid isthmus lines, 3 roof lines, 18 posterior wall lines, 11 anterior lines, 8 septal lines, and 15 mitral isthmus lines (Figure 2). Impressively, first-pass acute isolation with bidirectional block was achieved in 93% (54 of 58) of isthmus ablations and 94% (17 of 18) of left posterior wall lines. No ST segment alterations or other complications were observed during the periprocedural period. Conclusion In our cohort fPFA proved as a feasible, effective, and safe approach for treating organised atrial tacharrhythmias. The primary reason for designating this setup as our preferred choice for redo procedures lies in its versatility in addressing a wide range of arrhythmias. As ultra-fast pulmonary vein isolation (PVI) procedures become more prevalent with the expansion of PFA, the demand for an ideal setup capable of effectively targeting various substrates will become even more pronounced (2). Notably, our findings suggest superior suitability and efficacy when compared to bulkier, single-shot design PFA devices (3).Figure 1Figure 2

Ethereum Smart Home for Denial of Service and Single Point of Failure

Blockchain is a digital transaction technology adopting the peer-to-peer concept. The implementation of blockchain on Internet of Things (IoT) aims to secure the possibility of potential attacks against devices or transactions taking place on the IoT system. At practical levels, blockchain uses smart contracts to automate programs according to predetermined terms and conditions. This research is aimed at implementing an ethereum-based smart home Smart Contract by modifying the device components, dashboards, and consensus used in Xu et al.’s research. The consensus modification was performed by using Proof of Authority (PoA) aiming to improve block verification performance on the system. The Denial of Service (DoS) attacks and Single Point of Failure (SpoF) vulnerability were performed to evaluate the proposed system. The evaluation was performed with TCP Flood Attack, with request packets of 81,519 packets on port 8545 and ICMP Floods by sending 11,481,703 PING packets. The attack caused some application services running on the Ethereum Node 3 to stop, but did not stop the geth application. As for the Single Point of Failure (SPoF) vulnerability, the Ethereum network is still running and there were no obstacles in the mining process or block verification.

A Modified and Effective Blockchain Model for E-Healthcare Systems

The development of e-healthcare systems requires the application of advanced technologies, such as blockchain technology. The main challenge of applying blockchain technology to e-healthcare is to handle the impact of the delay that results from blockchain procedures during the communication and voting phases. The impacts of latency in blockchains negatively influence systems’ efficiency, performance, real-time processing, and quality of service. Therefore, this work proposes a modified model of a blockchain that allows delays to be avoided in critical situations in healthcare. Firstly, this work analyzes the specifications of healthcare data and processes to study and classify healthcare transactions according to their nature and sensitivity. Secondly, it introduces the concept of a fair-proof-of-stake consensus protocol for block creation and correctness procedures rather than famous ones such as proof-of-work or proof-of-stake. Thirdly, the work presents a simplified procedure for block verification, where it classifies transactions into three categories according to the time period limit and trustworthiness level. Consequently, there are three kinds of blocks, since every category is stored in a specific kind of block. The ideas of time period limits and trustworthiness fit with critical healthcare situations and the authority levels in healthcare systems. Therefore, we reduce the validation process of the trusted blocks and transactions. All proposed modifications help to reduce computational costs, speed up processing times, and enhance security and privacy. The experimental results show that the total execution time using a modified blockchain is reduced by about 49% compared to traditional blockchain models. Additionally, the number of messages using modified blockchain is reduced by about 53% compared to the traditional blockchain model.

RETRACTED: An enhanced consortium blockchain diversity mining technique for IoT metadata aggregation

Over the last two decades, Internet of Things (IoT) networks have grown exponentially. Although the devices have relatively low memory, resource, and processing capability, the trend is that nodes generate a large volume of data. That is where cloud technology comes into play to provide storage space. Because of its centralized nature and robustness, a large network operating with cloud assistance may be vulnerable. Due to rigid access control policies, the devices may be vulnerable to malicious activity. On the other hand, cloud technology provides a platform for such a security system to operate. A centralized secure architecture fails to consider mobile and edge devices within the context of these criteria. This raises numerous concerns about trusting third-party cloud intermediaries, which cause security and privacy leaks. The goal of this research is to look into the problem of blockchain consensus algorithms and their applicability in IoT with cloud-native infrastructure in the Ethereum and MultiChain variants. The significant challenge is scaling the core layer without sacrificing decentralization, security, or public verifiability. This type of testbed is used to investigate the impact of architectural design and consensus models in a lightweight IoT environment. Consensus in each IoT transaction remains the most important aspect of blockchain-enabled IoT networks. When the ledger is updated without privacy protection, transaction-oriented breaches can occur. Current practices for integrating finite IoT network resources into infrastructure-oriented blockchain implementations are flawed due to they are willing to sacrifice data security and integrity in order to save time and energy. This encourages researchers to investigate an improved lightweight block verification approach to the blockchain functional framework, that decreases processing needs, network latency, and network overhead substantially. As a result, the layer-3 consensus promotes blockchain to include the block with a 35% improvement in base layer block time efficiency and a 56% increase in throughput.

Multi-stage data synchronization for public blockchain in complex network environment

The various node connecting ways make the public blockchain live in a complex network environment. Single network model, no matter whether synchronized network, partial asynchronous network, or pure asynchronous network, are failed to accurately describe the practical public network environment. This results in the data synchronization and consensus achievement in public blockchain facing a dilemma, either relies on a weak timing assumption or adopts the strict asynchronous assumption but accepts a complex method.To address this dilemma, in this paper, we propose a multi-stage data synchronization (MSDS) mechanism for the public blockchain. First, we define the complex network for public blockchain in which nodes can join or leave freely. Then, data synchronization is been proven as a sufficient but not necessary condition for consensus. Second, a new kind of block structure called the block abstraction (BA) is proposed to quickly determine the relevance between different blocks. A new epoch-based DAG is proposed in which synchronizations of unrelated per-order blocks are reduced within an epoch. Then, a novel base-address PoW protocol is proposed to screen out nodes who have finished the synchronization and block verification of the previous epoch. Finally, a dual-phase consensus is conducted to achieve consensus that does not rely on timing assumptions on block generation and data synchronization while preventing the adoption of complex asynchronous consensus mechanisms. Extensive experiments are conducted on real data from Bitcoin and Ethereum and the results demonstrate the effectiveness and efficiency of our proposal.

Addressing blockchain privacy and efficiency challenges in mobile environments: an optimization strategy for lightweight clients and full nodes

In this paper, we propose an optimization strategy for privacy and efficiency challenges of blockchains in mobile environments. We propose a system model and define the corresponding threat model for the transaction query privacy problem of lightweight clients. Based on this, we design a transaction query scheme that effectively protects the privacy of lightweight clients. This scheme successfully achieves the security, privacy and completeness of transaction queries through an optimized blockchain restructuring process and privacy protection measures. Simulation experimental results show that our scheme significantly improves the privacy protection of transaction queries for lightweight clients while maintaining efficient query performance. In addition, we propose an optimization scheme for the lightweight full-node block verification efficiency problem. This scheme optimizes the verification process and introduces parallel computation, thus significantly improving the block verification efficiency. The experimental results show that our scheme achieves about 50% improvement in verification efficiency, both in terms of network size and transaction correlation. The research results in this paper not only provide a new perspective on privacy protection and efficiency improvement of blockchain technology, but also open up new applications in the mobile environment possibilities.

TinyLedger: A Lightweight Blockchain Ledger Protocol for the MEC Network

With the development of the Internet of Things, multi-access edge computing (MEC) is widely used in industrial IoT, intelligent transport systems, and IoT data management. As a decentralized, tamper-proof, multiparty trusted ledger technology, blockchain can enhance MEC security, privacy, and automatic use of resources. However, highly redundant storage and complex consensus prevent the blockchain from being directly deployed to edge computing nodes with limited resources. Unlike existing lightweight schemes, which do not consider liberating transaction data from blocks, this paper proposes a lightweight blockchain ledger protocol for MEC networks. The novelty of this work is that the transaction data in the block is compressed into a succinct proof through the zero-knowledge proof algorithm. To reduce the storage of block data, this paper proposes the proof-of-state-transfer model in which nodes verify the correctness of the global state transfer in the block without transactions. To reduce the communication complexity of consensus, this paper proposes a lightweight consensus protocol, which reduces the communication complexity of block voting and view switching to O(n). This paper develops the prototype system of TinyLedger to experiment and evaluate the performance of the system in terms of storage, verification, throughput, and communication. Experimental results show that compared to Ethereum, TinyLedger reduces storage capacity by 98.16%, communication volume by 74.53%, and block verification time by 87%.

Efficient consensus algorithm based on improved DPoS in UAV-assisted mobile edge computing

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.

Block verifiable dynamic searchable encryption using redactable blockchain

To solve the problems of low efficiency, inflexible updates and the high storage cost of existing result verifiable searchable encryption schemes, we propose a dynamic searchable encryption scheme with block verification using redactable blockchain. First, the inverted index is divided into blocks, the verification tag corresponding to the block index is uploaded to the redactable blockchain, and smart contracts are used to perform block verification of the query results to improve the query and verification performance. Furthermore, we use the blockchain rewriting technology to update the tags in the result checklist, improving the data update performance and scalability of the blockchain, and ensuring the constant storage overhead of the blockchain. Security analysis confirms that our proposals guarantee the correctness and completeness of the query results. Experimental results show that our proposed approach can improve the query efficiency and result verification efficiency under the premise of the low-speed growth of the blockchain data scale. In particular, the advantages become more significant as the data collection scale grows.

Research on Integration of Design and Manufacturing of High Thickness Honeycomb Sandwich Structure with Lager Curvature

Based on the characteristics of honeycomb sandwich structure with high thickness and large curvature, the idea of integration of design and manufacturing was proposed to solve the problem of mismatch among design, process and material. Facing the particularity of this kind of structure, the honeycomb deformation simulation model was established. And the composite building block verification method was simplified aiming at solving the problems of sliding and collapse of high thickness honeycomb. A variety of honeycomb stabilization methods were proposed. And the verification contents at the material level, element level, sub component level and component level were specified. Taking the landing gear door parts of large passenger aircraft as a case, the idea of design and manufacturing integration and the building block process verification method of honeycomb sandwich structure was practiced leading to the forward design of gear door parts. The honeycomb deformation simulation model was preliminarily established, which provided a reference for the forward design of similar structural parts.

Cooperative Task Offloading and Block Mining in Blockchain-Based Edge Computing With Multi-Agent Deep Reinforcement Learning

The convergence of mobile edge computing (MEC) and blockchain is transforming the current computing services in mobile networks, by offering task offloading solutions with security enhancement empowered by blockchain mining. Nevertheless, these important enabling technologies have been studied separately in most existing works. This article proposes a novel cooperative task offloading and block mining (TOBM) scheme for a blockchain-based MEC system where each edge device not only handles data tasks but also deals with block mining for improving the system utility. To address the latency issues caused by the blockchain operation in MEC, we develop a new Proof-of-Reputation consensus mechanism based on a lightweight block verification strategy. A multi-objective function is then formulated to maximize the system utility of the blockchain-based MEC system, by jointly optimizing offloading decision, channel selection, transmit power allocation, and computational resource allocation. We propose a novel distributed deep reinforcement learning-based approach by using a multi-agent deep deterministic policy gradient algorithm. We then develop a game-theoretic solution to model the offloading and mining competition among edge devices as a potential game, and prove the existence of a pure Nash equilibrium. Simulation results demonstrate the significant system utility improvements of our proposed scheme over baseline approaches.

An evolutionary algorithmic framework cloud based evidence collection architecture

Forensic in cloud computing is an advancement of evolutionary modern forensic science that protects against cyber criminals. Single centralize point compilation and storage of data, however, overcome the authenticity of digital evidence. In order to address this serious issue, this article suggests a evolutionary modern algorithm automated forensic platform leveraging infrastructure as a cloud service (IaaS) based on Blockchain concept. This proposed forensic structural design, evidence collection of evidence and stored on a blockchain which is circulated around several peer blocks. Secure Block Verification Mechanism (SBVM) is proposed to Safeguarding the device from unauthorised users. Using the Backtracking Search Optimization Algorithm search optimization algorithm for strengthening of the cloud environment, secret keys are optimally generated. On the bases of level of confidentiality, all data is stored and encrypted at cloud authentication server. Confidentiality-based Algebraically Homomorphic Cryptosystems learning is presented with a fast-forwarding algorithm for encryption. A block in the SDN controller is created for every data and information is stored in the cloud service provider and the history is recorded as metadata data about data. A hash based tree is constructed in each block by Secure Hash Algorithm version - 3 of 512 bits. By implementing graph theory-based graph neural networks in Smart Contracts, our framework enables users to track their data (GNNSC). Finally, the construction of a evidence graph using blockchain data enables evidence analysis. Experiments was carried out in a Python programming and blockchain integrated cloud environment with network simulator-3.30 (for Software Defined Network). As part of result our newly designed forensic architecture using blochchain (FAuB) good results in terms of evidence response time, insertion times of cloud evidence, verification time of evidence, computational overhead of evidence, hashes calculation time, keys generations times of evidence, evidence encryption time, evidence decryptions time, and total overall change rate of evidence, according to a comprehensive comparative study.

Benzene: Scaling Blockchain With Cooperation-Based Sharding

Sharding has been considered as a prominent approach to enhance the limited performance of blockchain. However, most sharding systems leverage a non-cooperative design, which lowers the fault tolerance resilience due to the decreased mining power as the consensus execution is limited to each separated shard. To this end, we present Benzene, a novel sharding system that enhances the performance by cooperation-based sharding while defending the per-shard security. First, we establish a double-chain architecture for function decoupling. This architecture separates transaction-recording functions from consensus-execution functions, thereby enabling the cross-shard cooperation during consensus execution while preserving the concurrency nature of sharding. Second, we design a cross-shard block verification mechanism leveraging Trusted Execution Environment (TEE), via which miners can verify blocks from other shards during the cooperation process with the minimized overheads. Finally, we design a voting-based consensus protocol for cross-shard cooperation. Transactions in each shard are confirmed by all shards that simultaneously cast votes, consequently achieving an enhanced fault tolerance and lowering the confirmation latency. We implement Benzene and conduct both prototype experiments and large-scale simulations to evaluate the performance of Benzene. Results show that Benzene achieves superior performance than existing sharding/non-sharding blockchain protocols. In particular, Benzene achieves a linearly-improved throughput with the increased number of shards (e.g., 32,370 transactions per second with 50 shards) and maintains a lower confirmation latency than Bitcoin (with more than 50 shards). Meanwhile, Benzene maintains a fixed fault tolerance at 1/3 even with the increased number of shards.

A Rate-and-Trust-Based Node Selection Model for Block Transmission in Blockchain Networks

Blockchain-enabled Internet of Things (IoT) has been receiving growing attention. However, IoT nodes are usually resources heterogeneous and subject to malicious attacks, such as the intentional delay of block verification and the transmission of invalid blocks. As a result, a random node-selection model for block transmission may lead to a low transmission rate and serious security risk. To solve the problem, this article proposes a rate-and-trust-based node selection model for block transmission. In our model, we calculate the block transmission rate of a node by the latency and connectivity among nodes and its trust value by its historical transmission and verification behaviors. On this basis, we propose a PageRank-based optimization algorithm for node selection that makes a tradeoff between the transmission rate and the security risk. Extensive experimental results show that the proposed model can achieve better performance than the state-of-the-art methods, including Bitcoin network, Ethereum network, and BlockP2P-EP protocol.

Block Verification Mechanism Based on Zero-Knowledge Proof in Blockchain

Since transactions in blockchain are based on public ledger verification, this raises security concerns about privacy protection. And it will cause the accumulation of data on the chain and resulting in the low efficiency of block verification, when the whole transaction on the chain is verified. In order to improve the efficiency and privacy protection of block data verification, this paper proposes an efficient block verification mechanism with privacy protection based on zero-knowledge proof (ZKP), which not only protects the privacy of users but also improves the speed of data block verification. There is no need to put the whole transaction on the chain when verifying block data. It just needs to generate the ZKP and root hash with the transaction information, then save them to the smart contract for verification. Moreover, the ZKP verification in smart contract is carried out to realize the privacy protection of the transaction and efficient verification of the block. When the data is validated, the buffer accepts the complete transaction, updates the transaction status in the cloud database, and packages up the chain. So, the ZKP strengthens the privacy protection ability of blockchain, and the smart contracts save the time cost of block verification.

A Distributed Power Trading Scheme Based on Blockchain and Artificial Intelligence in Smart Grids

As an emerging hot technology, smart grids (SGs) are being employed in many fields, such as smart homes and smart cities. Moreover, the application of artificial intelligence (AI) in SGs has promoted the development of the power industry. However, as users’ demands for electricity increase, traditional centralized power trading is unable to well meet the user demands and an increasing number of small distributed generators are being employed in trading activities. This not only leads to numerous security risks for the trading data but also has a negative impact on the cost of power generation, electrical security, and other aspects. Accordingly, this study proposes a distributed power trading scheme based on blockchain and AI. To protect the legitimate rights and interests of consumers and producers, credibility is used as an indicator to restrict untrustworthy behavior. Simultaneously, the reliability and communication capabilities of nodes are considered in block verification to improve the transaction confirmation efficiency, and a weighted communication tree construction algorithm is designed to achieve superior data forwarding. Finally, AI sensors are set up in power equipment to detect electricity generation and transmission, which alert users when security hazards occur, such as thunderstorms or typhoons. The experimental results show that the proposed scheme can not only improve the trading security but also reduce system communication delays.

Data Security Storage Mechanism Based on Blockchain Network

With the rapid development of information technology, the development of blockchain technology has also been deeply impacted. When performing block verification in the blockchain network, if all transactions are verified on the chain, this will cause the accumulation of data on the chain, resulting in data storage problems. At the same time, the security of data is also challenged, which will put enormous pressure on the block, resulting in extremely low communication efficiency of the block. The traditional blockchain system uses the Merkle Tree method to store data. While verifying the integrity and correctness of the data, the amount of proof is large, and it is impossible to verify the data in batches. A large amount of data proof will greatly impact the verification efficiency, which will cause end-to-end communication delays and seriously affect the blockchain system’s stability, efficiency, and security. In order to solve this problem, this paper proposes to replace the Merkle tree with polynomial commitments, which take advantage of the properties of polynomials to reduce the proof size and communication consumption. By realizing the ingenious use of aggregated proof and smart contracts, the verification efficiency of blocks is improved, and the pressure of node communication is reduced.

HADPoS: Improvement of DPoS Consensus Mechanism Based on Heat Attenuation

Blockchain was known by Satoshi Nakamoto in 2008 because of bitcoin. After more than a decade of development, blockchain has been widely applied in medical, digital finance, and electronic evidence, and others. At present, there are dozens of different consensus algorithms for different application context, such as proof of work, proof of stake, delegate proof of stake (DPoS), and proof of reputation. The DPoS consensus mechanism selects proxy nodes for block generation and confirmation through node voting, which can achieve fast block verification and adapt to a wide range of business areas. Aiming at the problems of DPoS consensus mechanism, such as giant monopoly, inactive voting, and high centralization, we puts forward the heat attenuation mechanism. The heat attenuation mechanism mildly punishes those nodes that maintain high ranking for a long time, which reduces the phenomenon of giant monopoly and enhances the degree of decentralization of the whole network. This article proposes the heat attenuation mechanism and the benefit distribution scheme. The heat attenuation mechanism improves the degree of decentralization of the blockchain network. The benefit distribution scheme makes sure that every node participating in the voting can get income. Finally, the feasibility and correctness of the consensus algorithm is proved by simulation experiments of the blockchain system.