Blockchain has been widely used in finance,the Internet of Things(IoT),supply chains,and other scenarios as a revolutionary technology.Consensus protocol plays a vital role in blockchain,which helps all participants t...Blockchain has been widely used in finance,the Internet of Things(IoT),supply chains,and other scenarios as a revolutionary technology.Consensus protocol plays a vital role in blockchain,which helps all participants to maintain the storage state consistently.However,with the improvement of network environment complexity and system scale,blockchain development is limited by the performance,security,and scalability of the consensus protocol.To address this problem,this paper introduces the collaborative filtering mechanism commonly used in the recommendation system into the Practical Byzantine Fault Tolerance(PBFT)and proposes a Byzantine fault-tolerant(BFT)consensus protocol based on collaborative filtering recommendation(CRBFT).Specifically,an improved collaborative filtering recommendation method is designed to use the similarity between a node’s recommendation opinions and those of the recommender as a basis for determining whether to adopt the recommendation opinions.This can amplify the recommendation voice of good nodes,weaken the impact of cunningmalicious nodes on the trust value calculation,andmake the calculated resultsmore accurate.In addition,the nodes are given voting power according to their trust value,and a weight randomelection algorithm is designed and implemented to reduce the risk of attack.The experimental results show that CRBFT can effectively eliminate various malicious nodes and improve the performance of blockchain systems in complex network environments,and the feasibility of CRBFT is also proven by theoretical analysis.展开更多
In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no...In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.展开更多
In this paper,we deal with questions related to blockchains in complex Internet of Things(IoT)-based ecosystems.Such ecosystems are typically composed of IoT devices,edge devices,cloud computing software services,as w...In this paper,we deal with questions related to blockchains in complex Internet of Things(IoT)-based ecosystems.Such ecosystems are typically composed of IoT devices,edge devices,cloud computing software services,as well as people,who are decision makers in scenarios such as smart cities.Many decisions related to analytics can be based on data coming from IoT sensors,software services,and people.However,they are typically based on different levels of abstraction and granularity.This poses a number of challenges when multiple blockchains are used together with smart contracts.This work proposes to apply our concept of elasticity to smart contracts and thereby enabling analytics in and between multiple blockchains in the context of IoT.We propose a reference architecture for Elastic Smart Contracts and evaluate the approach in a smart city scenario,discussing the benefits in terms of performance and self-adaptability of our solution.展开更多
The blockchain technology has been applied to wide areas.However,the open and transparent properties of the blockchains pose serious challenges to users’privacy.Among all the schemes for the privacy protection,the ze...The blockchain technology has been applied to wide areas.However,the open and transparent properties of the blockchains pose serious challenges to users’privacy.Among all the schemes for the privacy protection,the zero-knowledge proof algorithm conceals most of the private information in a transaction,while participants of the blockchain can validate this transaction without the private information.However,current schemes are only aimed at blockchains with the UTXO model,and only one type of assets circulates on these blockchains.Based on the zero-knowledge proof algorithm,this paper proposes a privacy protection scheme for blockchains that use the account and multi-asset model.We design the transaction structure,anonymous addresses and anonymous asset metadata,and also propose the methods of the asset transfer and double-spending detection.The zk-SNARKs algorithm is used to generate and to verify the zero-knowledge proof.And finally,we conduct the experiments to evaluate our scheme.展开更多
Background:In recent years,blockchain technology has attracted considerable attention.It records cryptographic transactions in a public ledger that is difficult to alter and compromise because of the distributed conse...Background:In recent years,blockchain technology has attracted considerable attention.It records cryptographic transactions in a public ledger that is difficult to alter and compromise because of the distributed consensus.As a result,blockchain is believed to resist fraud and hacking.Results:This work explores the types of fraud and malicious activities that can be prevented by blockchain technology and identifies attacks to which blockchain remains vulnerable.Conclusions:This study recommends appropriate defensive measures and calls for further research into the techniques for fighting malicious activities related to blockchains.展开更多
Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to so...Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to solve the problem of low throughput in blockchains. However, cross-shard communication hinders the effective improvement of blockchain throughput. Therefore, it is critical to reasonably allocate transactions to different shards to improve blockchain throughput. Existing research on blockchain sharding mainly focuses on shards formation, configuration, and consensus, while ignoring the negative impact of cross-shard communication on blockchain throughput. Aiming to maximize the throughput of transaction processing, we study how to allocate blockchain transactions to shards in this paper. We propose an Associated Transaction assignment algorithm based on Closest Fit (ATCF). ATCF classifies associated transactions into transaction groups which are then assigned to different shards in the non-ascending order of transaction group sizes periodically. Within each epoch, ATCF tries to select a shard that can handle all the transactions for each transaction group. If there are multiple such shards, ATCF selects the shard with the remaining processing capacity closest to the number of transactions in the transaction group. When no such shard exists, ATCF chooses the shard with the largest remaining processing capacity for the transaction group. The transaction groups that cannot be completely processed within the current epoch will be allocated in the subsequent epochs. We prove that ATCF is a 2-approximation algorithm for the associated transaction assignment problem. Simulation results show that ATCF can effectively improve the blockchain throughput and reduce the number of cross-shard transactions.展开更多
Cloud computing is a collection of distributed storage Network which can provide various services and store the data in the efficient manner.The advantages of cloud computing is its remote access where data can access...Cloud computing is a collection of distributed storage Network which can provide various services and store the data in the efficient manner.The advantages of cloud computing is its remote access where data can accessed in real time using Remote Method Innovation(RMI).The problem of data security in cloud environment is a major concern since the data can be accessed by any time by any user.Due to the lack of providing the efficient security the cloud computing they fail to achieve higher performance in providing the efficient service.To improve the performance in data security,the block chains are used for securing the data in the cloud environment.However,the traditional block chain technique are not suitable to provide efficient security to the cloud data stored in the cloud.In this paper,an efficient user centric block level Attribute Based Encryption(UCBL-ABE)scheme is presented to provide the efficient security of cloud data in cloud environment.The proposed approach performs data transaction by employing the block chain.The proposed system provides efficient privacy with access control to the user access according to the behavior of cloud user using Data Level Access Trust(DLAT).Based on DLAT,the user access has been restricted in the cloud environment.The proposed protocol is implemented in real time using Java programming language and uses IBM cloud.The implementation results justifies that the proposed system can able to provide efficient security to the data present in and cloud and also enhances the cloud performance.展开更多
As the Internet enters the era of big data, massive amounts of data are flooding people’s mobile phones and computers. The emerging self-media industry produces many videos every day, which also exposes many security...As the Internet enters the era of big data, massive amounts of data are flooding people’s mobile phones and computers. The emerging self-media industry produces many videos every day, which also exposes many security issues in digital rights management (DRM). The works of original creators can easily be infringed on public networks, and it is urgent to protect the copyright of digital content. Traditional digital rights management (TDRM) has many problems, including unqualified copyright confirmation, difficulty obtaining evidence, long time-consuming, high price, and high centralization. The combination of blockchain technology and digital rights management is one of the most popular blockchain application scenarios, the characteristics of the blockchain match DRM market demand. This paper proposes a registration oracle scheme for digital rights management based on heterogeneous blockchains, HBRO, which uses review and voting as a means to judge whether a work can be registered for copyright. HBRO is more rigorous than TDRM and DDRM in the copyright confirmation stage, rejecting many unnecessary and unqualified contents. In addition, a secure cross-chain solution is used to ensure the integrity and correctness of data transmission on heterogeneous blockchains.展开更多
With the rapid development of the Internet of Things(IoT),there is an increasing need for interac-tion between different networks.In order to improve the level of interconnection,especially the interoper-ability of us...With the rapid development of the Internet of Things(IoT),there is an increasing need for interac-tion between different networks.In order to improve the level of interconnection,especially the interoper-ability of users/devices between different nodes is very important.In the IoT heterogeneous blockchain sce-nario,how to ensure the legitimacy of the chain and how to confirm the identity of cross-chain informa-tion users/devices become the key issues to be solved for blockchain interoperability.In this paper,we pro-pose a secure and trusted interoperability mechanism for IoT based on heterogeneous chains to improve the security of blockchain interoperability.In this mecha-nism,a primary sidechain architecture supporting au-thentication at both ends of the heterogeneous chain is designed.In addition,a distributed gateway archi-tecture is proposed for cross-chain authentication and protocol conversion.The security and performance analysis shows that our scheme is feasible and effec-tive in improving the security of cross-chain opera-tions in IoT.展开更多
Edge blockchains,the blockchains running on edge computing infrastructures,have attracted a lot of attention in recent years.Thanks to data privacy,scalable computing resources,and distributed topology nature of edge ...Edge blockchains,the blockchains running on edge computing infrastructures,have attracted a lot of attention in recent years.Thanks to data privacy,scalable computing resources,and distributed topology nature of edge computing,edge blockchains are considered promising solutions to facilitating future blockchain applications.However,edge blockchains face unique security issues caused by the de⁃ployment of vulnerable edge devices and networks,including supply chain attacks and insecure consensus offloading,which are mostly not well studied in previous literature.This paper is the first survey that discusses the attacks and countermeasures of edge blockchains.We first summarize the three-layer architecture of edge blockchains:blockchain management,blockchain consensus,and blockchain lightweight cli⁃ent.We then describe seven specific attacks on edge blockchain components and discuss the countermeasures.At last,we provide future re⁃search directions on securing edge blockchains.This survey will act as a guideline for researchers and developers to design and implement se⁃cure edge blockchains.展开更多
Consensus protocols are used for the distributed management of large databases in an environment without trust among participants.The choice of a specific protocol depends on the purpose and characteristics of the sys...Consensus protocols are used for the distributed management of large databases in an environment without trust among participants.The choice of a specific protocol depends on the purpose and characteristics of the system itself.The subjects of the paper are consensus protocols in permissioned blockchains.The objective of this paper is to identify functional advantages and disadvantages of observed protocol.The analysis covers a total of six consensus protocols for permissioned blockchains.The following characteristics were compared:security,trust among participants,throughput and scalability.The results show that no protocol shows absolute dominance in all aspects of the comparison.Paxos and Raft are intended for systems in which there is no suspicion of unreliable users,but only the problem of a temporary shutdown.Practical Byzantine Fault Tolerance is intended for systems with a small number of nodes.Federated Byzantine Fault Tolerance shows better scalability and is more suitable for large systems,but can withstand a smaller number of malicious nodes.Proof-of-authority can withstand the largest number of malicious nodes without interfering with the functioning of the system.When choosing a consensus protocol for a blockchain application,one should take into account priority characteristics.展开更多
Despite the growing attention on blockchain,phishing activities have surged,particularly on newly established chains.Acknowledging the challenge of limited intelligence in the early stages of new chains,we propose ADA...Despite the growing attention on blockchain,phishing activities have surged,particularly on newly established chains.Acknowledging the challenge of limited intelligence in the early stages of new chains,we propose ADA-Spearan automatic phishing detection model utilizing adversarial domain adaptive learning which symbolizes the method’s ability to penetrate various heterogeneous blockchains for phishing detection.The model effectively identifies phishing behavior in new chains with limited reliable labels,addressing challenges such as significant distribution drift,low attribute overlap,and limited inter-chain connections.Our approach includes a subgraph construction strategy to align heterogeneous chains,a layered deep learning encoder capturing both temporal and spatial information,and integrated adversarial domain adaptive learning in end-to-end model training.Validation in Ethereum,Bitcoin,and EOSIO environments demonstrates ADA-Spear’s effectiveness,achieving an average F1 score of 77.41 on new chains after knowledge transfer,surpassing existing detection methods.展开更多
With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which ca...With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which causes the owner to lose control of the data.As a result,there are issues of intentional data leakage and tampering by third parties,and the private information contained in the data may lead to more significant issues.Furthermore,data is frequently maintained on multiple storage platforms,posing significant hurdles in terms of enlisting multiple parties to engage in data sharing while maintaining consistency.In this work,we propose a new architecture for applying blockchains to data sharing and achieve efficient and reliable data sharing among heterogeneous blockchains.We design a new data sharing transaction mechanism based on the system architecture to protect the security of the raw data and the processing process.We also design and implement a hybrid concurrency control protocol to overcome issues caused by the large differences in blockchain performance in our system and to improve the success rate of data sharing transactions.We took Ethereum and Hyperledger Fabric as examples to conduct crossblockchain data sharing experiments.The results show that our system achieves data sharing across heterogeneous blockchains with reasonable performance and has high scalability.展开更多
Blockchain is a type of distributed ledger technology that consists of a growing list of records,called blocks,that are securely linked together using cryptography.Each blockchain-based solution deploys a specific con...Blockchain is a type of distributed ledger technology that consists of a growing list of records,called blocks,that are securely linked together using cryptography.Each blockchain-based solution deploys a specific consensus algorithm that guarantees the consistency of the ledger over time.The most famous,and yet claimed to be the most secure,is the Proof-of-Work(PoW)consensus algorithm.In this paper,we revisit the fundamental calculations and assumptions of this algorithm,originally presented in the Bitcoin white paper.We break down its claimed calculations in order to better understand the underlying assumptions of the proposal.We also propose a novel formalization model of the PoW mining problem using the Birthday paradox.We utilize this model to formalize and analyze partial pre-image attacks on PoW-based blockchains,with formal analysis that confirms the experimental results and the previously proposed implications.We build on those analyses and propose new concepts for benchmarking the security of PoW-based systems,including Critical Difficulty and Critical Difficulty per given portion.Our calculations result in several important findings,including the profitability of launching partial pre-image attacks on PoW-based blockchains,once the mining puzzle difficulty reaches a given threshold.Specifically,for any compromised portion of the network(q<0.5;honest majority assumption still holds),the attack is formally proven profitable once the PoW mining puzzle difficulty reaches 56 leading zeros.展开更多
Opportunistic networks(OppNets)are usually a set of smart,wearable,and portable devices or entities with mobility that connect wirelessly without requiring infrastructure.Such a network is of great importance in data ...Opportunistic networks(OppNets)are usually a set of smart,wearable,and portable devices or entities with mobility that connect wirelessly without requiring infrastructure.Such a network is of great importance in data transmission,particularly in incidents and disasters,whether man-made or natural.However,message integrity and confidentiality are of concern when dealing with vital and physiological data transmission under strict privacy regulations.In this work,we propose a structure to classify messages based on their priority in different queues.Furthermore,due to the decentralized architecture of OppNets,we propose a blockchain-based structure for providing security for high-priority messages.It contains three sequences of functional blocks with a light and simplified implementation that make it suitable for battery-powered wearable devices that are limited in energy consumption and computational units.The simulation results show that by increasing the number of nodes in the network,the average of the changes in block sizes is neglectable,which addresses the computation bottleneck.Furthermore,we analyze the performance of the proposed structure in terms of message delivery and network overhead compared with the Epidemic and Prophet routing algorithms.These results indicate advancing the overall performance of the proposed algorithm.展开更多
Blockchain technology is increasingly popular and has been widely applied in many industrial fields,due to its unique properties of decentralization,immutability,and traceability.Blockchain systems in different fields...Blockchain technology is increasingly popular and has been widely applied in many industrial fields,due to its unique properties of decentralization,immutability,and traceability.Blockchain systems in different fields vary,with different block structures,consensus mechanisms and access permission models.These differences make it hard for different blockchain systems to interoperate with each other,which isolates them.Cross-chain technologies have been developed to solve this isolation problem in order to improve the interoperability of blockchains.Although some surveys on cross-chain technologies can be found,they are unable to keep up with the latest research progress due to their extremely fast pace of development.Moreover,the literature misses general criteria to evaluate the quality of cross-chain technologies.In this paper,a comprehensive literature review of cross-chain technologies is conducted by employing a comprehensive set of evaluation criteria.The preliminaries on blockchain interoperability are first presented.Then,a set of evaluation criteria is proposed in terms of security,privacy,performance,and functionality.The latest cutting-edge works are reviewed based on the proposed taxonomy of cross-chain technologies and their performance is evaluated against our proposed criteria.Finally,some open issues and future directions of cross-chain research are pointed out.展开更多
Taxation,the primary source of fiscal revenue,has profound implications in guiding resource allocation,promoting economic growth,adjusting social wealth distribution,and enhancing cultural influence.The development of...Taxation,the primary source of fiscal revenue,has profound implications in guiding resource allocation,promoting economic growth,adjusting social wealth distribution,and enhancing cultural influence.The development of e-taxation provides a enhanced security for taxation,but it still faces the risk of inefficiency and tax data leakage.As a decentralized ledger,blockchain provides an effective solution for protecting tax data and avoiding tax-related errors and fraud.The introduction of blockchain into e-taxation protocols can ensure the public verification of taxes.However,balancing taxpayer identity privacy with regulation remains a challenge.In this paper,we propose a blockchain-based anonymous and regulatory e-taxation protocol.This protocol ensures the supervision and tracking of malicious taxpayers while maintaining honest taxpayer identity privacy,reduces the storage needs for public key certificates in the public key infrastructure,and enables selfcertification of taxpayers’public keys and addresses.We formalize the security model of unforgeability for transactions,anonymity for honest taxpayers,and traceability for malicious taxpayers.Security analysis shows that the proposed protocol satisfies unforgeability,anonymity,and traceability.The experimental results of time consumption show that the protocol is feasible in practical applications.展开更多
The concept of Supply Chain 4.0 represents a transformative phase in supply chain management through advanced digital technologies like IoT, AI, blockchain, and cyber-physical systems. While these innovations deliver ...The concept of Supply Chain 4.0 represents a transformative phase in supply chain management through advanced digital technologies like IoT, AI, blockchain, and cyber-physical systems. While these innovations deliver operational improvements, the heightened interconnectivity introduces significant cybersecurity challenges, particularly within military logistics, where mission-critical operations and life-safety concerns are paramount. This paper examines these unique cybersecurity requirements, focusing on advanced persistent threats, supply chain poisoning, and data breaches that could compromise sensitive operations. The study proposes a hybrid cybersecurity framework tailored to military logistics, integrating resilience, redundancy, and cross-jurisdictional security measures. Real-world applicability is validated through simulations, offering strategies for securing supply chains while balancing security, efficiency, and flexibility.展开更多
Within the framework of the 2030 Agenda and to achieve the Sustainable Development Goals(SDGs),science,technology and innovation play an even more central role.Building on this foundation,the primary objective of this...Within the framework of the 2030 Agenda and to achieve the Sustainable Development Goals(SDGs),science,technology and innovation play an even more central role.Building on this foundation,the primary objective of this paper is to explore the potential applications of blockchain in supporting the achievement of these sustainability goals.Starting from a review of the relevant literature on this topic,the main fields in which blockchain can contribute to sustainable development will be identified.The main blockchain applications will then be analyzed and categorized according to these SDGs.This research will then critically present the main blockchain-based projects that emerged in the first stage of the study and were implemented by the United Nations.The main objectives and benefits of each project will be analyzed.This is where the originality of this paper lies.To the best of the author’s knowledge,this is one of the first attempts to present a comprehensive overview of the United Nations’projects related to SDGs 1,2,5,7,9,13,and 16.This paper,which bridges the gap between innovation management and the sustainability field,will contribute to the increasingly current debate on sustainability issues and be beneficial to scholars,practitioners,and policymakers alike.展开更多
With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become ...With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become a research hotspot, and the security of the oracle responsible for providing reliable data has attracted much attention. The most widely used centralized oracles in blockchain, such as Provable and Town Crier, all rely on a single oracle to obtain data, which suffers from a single point of failure and limits the large-scale development of blockchain. To this end, the distributed oracle scheme is put forward, but the existing distributed oracle schemes such as Chainlink and Augur generally have low execution efficiency and high communication overhead, which leads to their poor applicability. To solve the above problems, this paper proposes a trusted distributed oracle scheme based on a share recovery threshold signature. First, a data verification method of distributed oracles is designed based on threshold signature. By aggregating the signatures of oracles, data from different data sources can be mutually verified, leading to a more efficient data verification and aggregation process. Then, a credibility-based cluster head election algorithm is designed, which reduces the communication overhead by clarifying the function distribution and building a hierarchical structure. Considering the good performance of the BLS threshold signature in large-scale applications, this paper combines it with distributed oracle technology and proposes a BLS threshold signature algorithm that supports share recovery in distributed oracles. The share recovery mechanism enables the proposed scheme to solve the key loss issue, and the setting of the threshold value enables the proposed scheme to complete signature aggregation with only a threshold number of oracles, making the scheme more robust. Finally, experimental results indicate that, by using the threshold signature technology and the cluster head election algorithm, our scheme effectively improves the execution efficiency of oracles and solves the problem of a single point of failure, leading to higher scalability and robustness.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62102449)awarded to W.J.Wang.
文摘Blockchain has been widely used in finance,the Internet of Things(IoT),supply chains,and other scenarios as a revolutionary technology.Consensus protocol plays a vital role in blockchain,which helps all participants to maintain the storage state consistently.However,with the improvement of network environment complexity and system scale,blockchain development is limited by the performance,security,and scalability of the consensus protocol.To address this problem,this paper introduces the collaborative filtering mechanism commonly used in the recommendation system into the Practical Byzantine Fault Tolerance(PBFT)and proposes a Byzantine fault-tolerant(BFT)consensus protocol based on collaborative filtering recommendation(CRBFT).Specifically,an improved collaborative filtering recommendation method is designed to use the similarity between a node’s recommendation opinions and those of the recommender as a basis for determining whether to adopt the recommendation opinions.This can amplify the recommendation voice of good nodes,weaken the impact of cunningmalicious nodes on the trust value calculation,andmake the calculated resultsmore accurate.In addition,the nodes are given voting power according to their trust value,and a weight randomelection algorithm is designed and implemented to reduce the risk of attack.The experimental results show that CRBFT can effectively eliminate various malicious nodes and improve the performance of blockchain systems in complex network environments,and the feasibility of CRBFT is also proven by theoretical analysis.
基金the National Natural Science Foundation of China under Grant 61701059,Grant 61941114,and Grant 61831002,in part by the Fundamental Research Funds for the Central Universities of New TeachersProject,in part by the Chongqing Technological Innovation and Application Development Projects under Grant cstc2019jscx-msxm1322,and in part by the Eighteentg Open Foundation of State Key Lab of Integrated Services Networks of Xidian University under Grant ISN20-05.
文摘In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.
基金This work was partially supported by FEDER/Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación under project HORATIO(RTI2018-101204-B-C21)by Junta de Andalucía under projects APOLO(US-1264651)and EKIPMENT-PLUS(P18-FR-2895)by the TU Wien Research Cluster Smart CT.
文摘In this paper,we deal with questions related to blockchains in complex Internet of Things(IoT)-based ecosystems.Such ecosystems are typically composed of IoT devices,edge devices,cloud computing software services,as well as people,who are decision makers in scenarios such as smart cities.Many decisions related to analytics can be based on data coming from IoT sensors,software services,and people.However,they are typically based on different levels of abstraction and granularity.This poses a number of challenges when multiple blockchains are used together with smart contracts.This work proposes to apply our concept of elasticity to smart contracts and thereby enabling analytics in and between multiple blockchains in the context of IoT.We propose a reference architecture for Elastic Smart Contracts and evaluate the approach in a smart city scenario,discussing the benefits in terms of performance and self-adaptability of our solution.
基金supported by National Natural Science Foundation of China(61672499,61772502)Key Special Project of Beijing Municipal Science&Technology Commission(Z181100003218018)+1 种基金Natural Science Foundation of Inner Mongolia,Open Foundation of State key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications,SKLNST-2016-2-09)SV-ICT Blockchain&DAPP Joint Lab
文摘The blockchain technology has been applied to wide areas.However,the open and transparent properties of the blockchains pose serious challenges to users’privacy.Among all the schemes for the privacy protection,the zero-knowledge proof algorithm conceals most of the private information in a transaction,while participants of the blockchain can validate this transaction without the private information.However,current schemes are only aimed at blockchains with the UTXO model,and only one type of assets circulates on these blockchains.Based on the zero-knowledge proof algorithm,this paper proposes a privacy protection scheme for blockchains that use the account and multi-asset model.We design the transaction structure,anonymous addresses and anonymous asset metadata,and also propose the methods of the asset transfer and double-spending detection.The zk-SNARKs algorithm is used to generate and to verify the zero-knowledge proof.And finally,we conduct the experiments to evaluate our scheme.
文摘Background:In recent years,blockchain technology has attracted considerable attention.It records cryptographic transactions in a public ledger that is difficult to alter and compromise because of the distributed consensus.As a result,blockchain is believed to resist fraud and hacking.Results:This work explores the types of fraud and malicious activities that can be prevented by blockchain technology and identifies attacks to which blockchain remains vulnerable.Conclusions:This study recommends appropriate defensive measures and calls for further research into the techniques for fighting malicious activities related to blockchains.
基金supported by Anhui Provincial Key R&D Program of China(202004a05020040),the open project of State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System in China(CEMEE2018Z0102B)the open fund of Intelligent Interconnected Systems Laboratory of Anhui Province(PA2021AKSK0114),Hefei University of Technology.
文摘Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to solve the problem of low throughput in blockchains. However, cross-shard communication hinders the effective improvement of blockchain throughput. Therefore, it is critical to reasonably allocate transactions to different shards to improve blockchain throughput. Existing research on blockchain sharding mainly focuses on shards formation, configuration, and consensus, while ignoring the negative impact of cross-shard communication on blockchain throughput. Aiming to maximize the throughput of transaction processing, we study how to allocate blockchain transactions to shards in this paper. We propose an Associated Transaction assignment algorithm based on Closest Fit (ATCF). ATCF classifies associated transactions into transaction groups which are then assigned to different shards in the non-ascending order of transaction group sizes periodically. Within each epoch, ATCF tries to select a shard that can handle all the transactions for each transaction group. If there are multiple such shards, ATCF selects the shard with the remaining processing capacity closest to the number of transactions in the transaction group. When no such shard exists, ATCF chooses the shard with the largest remaining processing capacity for the transaction group. The transaction groups that cannot be completely processed within the current epoch will be allocated in the subsequent epochs. We prove that ATCF is a 2-approximation algorithm for the associated transaction assignment problem. Simulation results show that ATCF can effectively improve the blockchain throughput and reduce the number of cross-shard transactions.
文摘Cloud computing is a collection of distributed storage Network which can provide various services and store the data in the efficient manner.The advantages of cloud computing is its remote access where data can accessed in real time using Remote Method Innovation(RMI).The problem of data security in cloud environment is a major concern since the data can be accessed by any time by any user.Due to the lack of providing the efficient security the cloud computing they fail to achieve higher performance in providing the efficient service.To improve the performance in data security,the block chains are used for securing the data in the cloud environment.However,the traditional block chain technique are not suitable to provide efficient security to the cloud data stored in the cloud.In this paper,an efficient user centric block level Attribute Based Encryption(UCBL-ABE)scheme is presented to provide the efficient security of cloud data in cloud environment.The proposed approach performs data transaction by employing the block chain.The proposed system provides efficient privacy with access control to the user access according to the behavior of cloud user using Data Level Access Trust(DLAT).Based on DLAT,the user access has been restricted in the cloud environment.The proposed protocol is implemented in real time using Java programming language and uses IBM cloud.The implementation results justifies that the proposed system can able to provide efficient security to the data present in and cloud and also enhances the cloud performance.
文摘As the Internet enters the era of big data, massive amounts of data are flooding people’s mobile phones and computers. The emerging self-media industry produces many videos every day, which also exposes many security issues in digital rights management (DRM). The works of original creators can easily be infringed on public networks, and it is urgent to protect the copyright of digital content. Traditional digital rights management (TDRM) has many problems, including unqualified copyright confirmation, difficulty obtaining evidence, long time-consuming, high price, and high centralization. The combination of blockchain technology and digital rights management is one of the most popular blockchain application scenarios, the characteristics of the blockchain match DRM market demand. This paper proposes a registration oracle scheme for digital rights management based on heterogeneous blockchains, HBRO, which uses review and voting as a means to judge whether a work can be registered for copyright. HBRO is more rigorous than TDRM and DDRM in the copyright confirmation stage, rejecting many unnecessary and unqualified contents. In addition, a secure cross-chain solution is used to ensure the integrity and correctness of data transmission on heterogeneous blockchains.
基金The research work is supported by the Shandong Provincial Key Research and Development Program(2021CXGC010107).
文摘With the rapid development of the Internet of Things(IoT),there is an increasing need for interac-tion between different networks.In order to improve the level of interconnection,especially the interoper-ability of users/devices between different nodes is very important.In the IoT heterogeneous blockchain sce-nario,how to ensure the legitimacy of the chain and how to confirm the identity of cross-chain informa-tion users/devices become the key issues to be solved for blockchain interoperability.In this paper,we pro-pose a secure and trusted interoperability mechanism for IoT based on heterogeneous chains to improve the security of blockchain interoperability.In this mecha-nism,a primary sidechain architecture supporting au-thentication at both ends of the heterogeneous chain is designed.In addition,a distributed gateway archi-tecture is proposed for cross-chain authentication and protocol conversion.The security and performance analysis shows that our scheme is feasible and effec-tive in improving the security of cross-chain opera-tions in IoT.
基金supported by the Research Institute for Artificial Intelligence of Things,The Hong Kong Polytechnic University,HK RGC Collaborative Research Fund(CRF)under Grant No.C2004-21GF.
文摘Edge blockchains,the blockchains running on edge computing infrastructures,have attracted a lot of attention in recent years.Thanks to data privacy,scalable computing resources,and distributed topology nature of edge computing,edge blockchains are considered promising solutions to facilitating future blockchain applications.However,edge blockchains face unique security issues caused by the de⁃ployment of vulnerable edge devices and networks,including supply chain attacks and insecure consensus offloading,which are mostly not well studied in previous literature.This paper is the first survey that discusses the attacks and countermeasures of edge blockchains.We first summarize the three-layer architecture of edge blockchains:blockchain management,blockchain consensus,and blockchain lightweight cli⁃ent.We then describe seven specific attacks on edge blockchain components and discuss the countermeasures.At last,we provide future re⁃search directions on securing edge blockchains.This survey will act as a guideline for researchers and developers to design and implement se⁃cure edge blockchains.
文摘Consensus protocols are used for the distributed management of large databases in an environment without trust among participants.The choice of a specific protocol depends on the purpose and characteristics of the system itself.The subjects of the paper are consensus protocols in permissioned blockchains.The objective of this paper is to identify functional advantages and disadvantages of observed protocol.The analysis covers a total of six consensus protocols for permissioned blockchains.The following characteristics were compared:security,trust among participants,throughput and scalability.The results show that no protocol shows absolute dominance in all aspects of the comparison.Paxos and Raft are intended for systems in which there is no suspicion of unreliable users,but only the problem of a temporary shutdown.Practical Byzantine Fault Tolerance is intended for systems with a small number of nodes.Federated Byzantine Fault Tolerance shows better scalability and is more suitable for large systems,but can withstand a smaller number of malicious nodes.Proof-of-authority can withstand the largest number of malicious nodes without interfering with the functioning of the system.When choosing a consensus protocol for a blockchain application,one should take into account priority characteristics.
基金supported by National Key Research and Development Program of China(Nos.2023YFC3306305,2021YFF0307203,2019QY1300)Foundation Strengthening Program Technical Area Fund(No.2021-JCJQJJ-0908)+4 种基金technological project funding of the State Grid Corporation of China(Contract Number:SG270000YXJS2311060)Youth Innovation Promotion Association CAS(No.2021156)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDC02040100)National Natural Science Foundation of China(No.61802404)supported by the Program of Key Laboratory of Network Assessment Technology,the Chinese Academy of Sciences,Program of Beijing Key Laboratory of Network Security and Protection Technology.
文摘Despite the growing attention on blockchain,phishing activities have surged,particularly on newly established chains.Acknowledging the challenge of limited intelligence in the early stages of new chains,we propose ADA-Spearan automatic phishing detection model utilizing adversarial domain adaptive learning which symbolizes the method’s ability to penetrate various heterogeneous blockchains for phishing detection.The model effectively identifies phishing behavior in new chains with limited reliable labels,addressing challenges such as significant distribution drift,low attribute overlap,and limited inter-chain connections.Our approach includes a subgraph construction strategy to align heterogeneous chains,a layered deep learning encoder capturing both temporal and spatial information,and integrated adversarial domain adaptive learning in end-to-end model training.Validation in Ethereum,Bitcoin,and EOSIO environments demonstrates ADA-Spear’s effectiveness,achieving an average F1 score of 77.41 on new chains after knowledge transfer,surpassing existing detection methods.
基金supported by the National Key Research and Development Program of China(Nos.2020YFB1707900,2021YFB2700700)the National Natural Science Foundation of China(NSFC)(Grant No.62072035)+4 种基金the Open Research Projects of Zhejiang Lab(No.2020KE0AB04)CCF-Huawei Database System Innovation Research Plan(No.CCF-HuaweiDBIR2021007B)Ye Yuan is supported by the NSFC(Grant Nos.61932004,62225203,U21A20516)Xiaochun Yang is supported by the National Key Research and Development Program of China(No.2020YFB1707900)Guoren Wang is supported by the NSFC(Nos.61732003,U2001211).
文摘With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which causes the owner to lose control of the data.As a result,there are issues of intentional data leakage and tampering by third parties,and the private information contained in the data may lead to more significant issues.Furthermore,data is frequently maintained on multiple storage platforms,posing significant hurdles in terms of enlisting multiple parties to engage in data sharing while maintaining consistency.In this work,we propose a new architecture for applying blockchains to data sharing and achieve efficient and reliable data sharing among heterogeneous blockchains.We design a new data sharing transaction mechanism based on the system architecture to protect the security of the raw data and the processing process.We also design and implement a hybrid concurrency control protocol to overcome issues caused by the large differences in blockchain performance in our system and to improve the success rate of data sharing transactions.We took Ethereum and Hyperledger Fabric as examples to conduct crossblockchain data sharing experiments.The results show that our system achieves data sharing across heterogeneous blockchains with reasonable performance and has high scalability.
基金funding from the National Research,Development and Innovation Office within the framework of the Artificial Intelligence National Laboratory Programme(MILAB),and from the national project TKP2021-NVA-09 implemented with the support provided by the Ministry of Innovation and Technol-ogy of Hungary from the National Research,Development and Innova-tion Fund.
文摘Blockchain is a type of distributed ledger technology that consists of a growing list of records,called blocks,that are securely linked together using cryptography.Each blockchain-based solution deploys a specific consensus algorithm that guarantees the consistency of the ledger over time.The most famous,and yet claimed to be the most secure,is the Proof-of-Work(PoW)consensus algorithm.In this paper,we revisit the fundamental calculations and assumptions of this algorithm,originally presented in the Bitcoin white paper.We break down its claimed calculations in order to better understand the underlying assumptions of the proposal.We also propose a novel formalization model of the PoW mining problem using the Birthday paradox.We utilize this model to formalize and analyze partial pre-image attacks on PoW-based blockchains,with formal analysis that confirms the experimental results and the previously proposed implications.We build on those analyses and propose new concepts for benchmarking the security of PoW-based systems,including Critical Difficulty and Critical Difficulty per given portion.Our calculations result in several important findings,including the profitability of launching partial pre-image attacks on PoW-based blockchains,once the mining puzzle difficulty reaches a given threshold.Specifically,for any compromised portion of the network(q<0.5;honest majority assumption still holds),the attack is formally proven profitable once the PoW mining puzzle difficulty reaches 56 leading zeros.
文摘Opportunistic networks(OppNets)are usually a set of smart,wearable,and portable devices or entities with mobility that connect wirelessly without requiring infrastructure.Such a network is of great importance in data transmission,particularly in incidents and disasters,whether man-made or natural.However,message integrity and confidentiality are of concern when dealing with vital and physiological data transmission under strict privacy regulations.In this work,we propose a structure to classify messages based on their priority in different queues.Furthermore,due to the decentralized architecture of OppNets,we propose a blockchain-based structure for providing security for high-priority messages.It contains three sequences of functional blocks with a light and simplified implementation that make it suitable for battery-powered wearable devices that are limited in energy consumption and computational units.The simulation results show that by increasing the number of nodes in the network,the average of the changes in block sizes is neglectable,which addresses the computation bottleneck.Furthermore,we analyze the performance of the proposed structure in terms of message delivery and network overhead compared with the Epidemic and Prophet routing algorithms.These results indicate advancing the overall performance of the proposed algorithm.
基金supported in part by the National Natural Science Foundation of China under Grant 62072351in part by the Key Research Project of Shaanxi Natural Science Foundation under Grant 2023-JCZD-35in part by the open research project of ZheJiang Lab under grant 2021PD0AB01。
文摘Blockchain technology is increasingly popular and has been widely applied in many industrial fields,due to its unique properties of decentralization,immutability,and traceability.Blockchain systems in different fields vary,with different block structures,consensus mechanisms and access permission models.These differences make it hard for different blockchain systems to interoperate with each other,which isolates them.Cross-chain technologies have been developed to solve this isolation problem in order to improve the interoperability of blockchains.Although some surveys on cross-chain technologies can be found,they are unable to keep up with the latest research progress due to their extremely fast pace of development.Moreover,the literature misses general criteria to evaluate the quality of cross-chain technologies.In this paper,a comprehensive literature review of cross-chain technologies is conducted by employing a comprehensive set of evaluation criteria.The preliminaries on blockchain interoperability are first presented.Then,a set of evaluation criteria is proposed in terms of security,privacy,performance,and functionality.The latest cutting-edge works are reviewed based on the proposed taxonomy of cross-chain technologies and their performance is evaluated against our proposed criteria.Finally,some open issues and future directions of cross-chain research are pointed out.
文摘Taxation,the primary source of fiscal revenue,has profound implications in guiding resource allocation,promoting economic growth,adjusting social wealth distribution,and enhancing cultural influence.The development of e-taxation provides a enhanced security for taxation,but it still faces the risk of inefficiency and tax data leakage.As a decentralized ledger,blockchain provides an effective solution for protecting tax data and avoiding tax-related errors and fraud.The introduction of blockchain into e-taxation protocols can ensure the public verification of taxes.However,balancing taxpayer identity privacy with regulation remains a challenge.In this paper,we propose a blockchain-based anonymous and regulatory e-taxation protocol.This protocol ensures the supervision and tracking of malicious taxpayers while maintaining honest taxpayer identity privacy,reduces the storage needs for public key certificates in the public key infrastructure,and enables selfcertification of taxpayers’public keys and addresses.We formalize the security model of unforgeability for transactions,anonymity for honest taxpayers,and traceability for malicious taxpayers.Security analysis shows that the proposed protocol satisfies unforgeability,anonymity,and traceability.The experimental results of time consumption show that the protocol is feasible in practical applications.
文摘The concept of Supply Chain 4.0 represents a transformative phase in supply chain management through advanced digital technologies like IoT, AI, blockchain, and cyber-physical systems. While these innovations deliver operational improvements, the heightened interconnectivity introduces significant cybersecurity challenges, particularly within military logistics, where mission-critical operations and life-safety concerns are paramount. This paper examines these unique cybersecurity requirements, focusing on advanced persistent threats, supply chain poisoning, and data breaches that could compromise sensitive operations. The study proposes a hybrid cybersecurity framework tailored to military logistics, integrating resilience, redundancy, and cross-jurisdictional security measures. Real-world applicability is validated through simulations, offering strategies for securing supply chains while balancing security, efficiency, and flexibility.
文摘Within the framework of the 2030 Agenda and to achieve the Sustainable Development Goals(SDGs),science,technology and innovation play an even more central role.Building on this foundation,the primary objective of this paper is to explore the potential applications of blockchain in supporting the achievement of these sustainability goals.Starting from a review of the relevant literature on this topic,the main fields in which blockchain can contribute to sustainable development will be identified.The main blockchain applications will then be analyzed and categorized according to these SDGs.This research will then critically present the main blockchain-based projects that emerged in the first stage of the study and were implemented by the United Nations.The main objectives and benefits of each project will be analyzed.This is where the originality of this paper lies.To the best of the author’s knowledge,this is one of the first attempts to present a comprehensive overview of the United Nations’projects related to SDGs 1,2,5,7,9,13,and 16.This paper,which bridges the gap between innovation management and the sustainability field,will contribute to the increasingly current debate on sustainability issues and be beneficial to scholars,practitioners,and policymakers alike.
基金supported by the National Natural Science Foundation of China(Grant No.62102449)the Central Plains Talent Program under Grant No.224200510003.
文摘With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become a research hotspot, and the security of the oracle responsible for providing reliable data has attracted much attention. The most widely used centralized oracles in blockchain, such as Provable and Town Crier, all rely on a single oracle to obtain data, which suffers from a single point of failure and limits the large-scale development of blockchain. To this end, the distributed oracle scheme is put forward, but the existing distributed oracle schemes such as Chainlink and Augur generally have low execution efficiency and high communication overhead, which leads to their poor applicability. To solve the above problems, this paper proposes a trusted distributed oracle scheme based on a share recovery threshold signature. First, a data verification method of distributed oracles is designed based on threshold signature. By aggregating the signatures of oracles, data from different data sources can be mutually verified, leading to a more efficient data verification and aggregation process. Then, a credibility-based cluster head election algorithm is designed, which reduces the communication overhead by clarifying the function distribution and building a hierarchical structure. Considering the good performance of the BLS threshold signature in large-scale applications, this paper combines it with distributed oracle technology and proposes a BLS threshold signature algorithm that supports share recovery in distributed oracles. The share recovery mechanism enables the proposed scheme to solve the key loss issue, and the setting of the threshold value enables the proposed scheme to complete signature aggregation with only a threshold number of oracles, making the scheme more robust. Finally, experimental results indicate that, by using the threshold signature technology and the cluster head election algorithm, our scheme effectively improves the execution efficiency of oracles and solves the problem of a single point of failure, leading to higher scalability and robustness.
