Payment Channel Networks(PCNs)are a promising alternative to improve the scalability of a blockchain network.A PCN employs off-chain micropayment channels that do not need a global block confirmation procedure,thereby...Payment Channel Networks(PCNs)are a promising alternative to improve the scalability of a blockchain network.A PCN employs off-chain micropayment channels that do not need a global block confirmation procedure,thereby sacrificing the ability to confirm transactions instantaneously.PCN uses a routing algorithm to identify a path between two users who do not have a direct channel between them to settle a transaction.The performance of most of the existing centralized path-finding algorithms does not scale with network size.The rapid growth of Bitcoin PCN necessitates considering distributed algorithms.However,the existing decentralized algorithms suffer from resource underutilization.We present a decentralized routing algorithm,Swift,focusing on fee optimization.The concept of a secret path is used to reduce the path length between a sender and a receiver to optimize the fees.Furthermore,we reduce a network structure into combinations of cycles to theoretically study fee optimization with changes in cloud size.The secret path also helps in edge load sharing,which results in an improvement of throughput.Swift routing achieves up to 21%and 63%in fee and throughput optimization,respectively.The results from the simulations follow the trends identified in the theoretical analysis.展开更多
Scalability has long been a major challenge of cryptocurrency systems,which is mainly caused by the delay in reaching consensus when processing transactions on-chain.As an effective mitigation approach,the payment cha...Scalability has long been a major challenge of cryptocurrency systems,which is mainly caused by the delay in reaching consensus when processing transactions on-chain.As an effective mitigation approach,the payment channel networks(PCNs)enable private channels among blockchain nodes to process transactions off-chain,relieving long-time waiting for the online transaction confirmation.The state-of-the-art studies of PCN focus on improving the efficiency and availability via optimizing routing,scheduling,and initial deposits,as well as preventing the system from security and privacy attacks.However,the behavioral decision dynamics of blockchain nodes under potential malicious attacks is largely neglected.To fill this gap,we employ the game theory to study the characteristics of channel interactions from both the micro and macro perspectives under the situation of channel depletion attacks.Our study is progressive,as we conduct the game-theoretic analysis of node behavioral characteristics from individuals to the whole population of PCN.Our analysis is complementary,since we utilize not only the classic game theory with the complete rationality assumption,but also the evolutionary game theory considering the limited rationality of players to portray the evolution of PCN.The results of numerous simulation experiments verify the effectiveness of our analysis.展开更多
Traditional centralized token exchange(CEX)has been suffering from hacking due to the centralized management of users’tokens.In contrast,decentralized token exchange(DEX)maintains users’assets by smart contracts in ...Traditional centralized token exchange(CEX)has been suffering from hacking due to the centralized management of users’tokens.In contrast,decentralized token exchange(DEX)maintains users’assets by smart contracts in a decentralized manner,but introduces additional overhead in terms of gas fee and transaction confirmation latency.Hybrid decentralized token exchange(HEX)has been proposed to combine the benefits of CEX and DEX.However,existing HEX is criticized for two issues.First,trading transactions are time-consuming and expensive for frequent token traders.Second,excessive simultaneous transactions might cause the pending transaction congestion in the Ethereum network.In this paper,we propose a payment channel based HEX,which extends existing solutions by adding a new payment channel layer to benefit frequent traders and alleviate the pending transaction congestion.Besides,we propose the very first gas-price vs.transactionconfirmation-latency function to guide Ethereum transaction issuers to choose an optimal gas price that minimizes the overall cost.Extensive simulations are conducted to compare the cost in the proposed HEX with that in the conventional HEX.The results demonstrate the effectiveness of our proposed mechanism in terms of reducing gas fees and transaction confirmation latency for frequent traders as well as the pending transaction congestion in Ethereum.展开更多
文摘Payment Channel Networks(PCNs)are a promising alternative to improve the scalability of a blockchain network.A PCN employs off-chain micropayment channels that do not need a global block confirmation procedure,thereby sacrificing the ability to confirm transactions instantaneously.PCN uses a routing algorithm to identify a path between two users who do not have a direct channel between them to settle a transaction.The performance of most of the existing centralized path-finding algorithms does not scale with network size.The rapid growth of Bitcoin PCN necessitates considering distributed algorithms.However,the existing decentralized algorithms suffer from resource underutilization.We present a decentralized routing algorithm,Swift,focusing on fee optimization.The concept of a secret path is used to reduce the path length between a sender and a receiver to optimize the fees.Furthermore,we reduce a network structure into combinations of cycles to theoretically study fee optimization with changes in cloud size.The secret path also helps in edge load sharing,which results in an improvement of throughput.Swift routing achieves up to 21%and 63%in fee and throughput optimization,respectively.The results from the simulations follow the trends identified in the theoretical analysis.
基金The work was partially supported by the National Key Research and Development Program of China under Grant No.2019YFB2102600the National Natural Science Foundation of China under Grant Nos.62122042,61971269 and 61832012.
文摘Scalability has long been a major challenge of cryptocurrency systems,which is mainly caused by the delay in reaching consensus when processing transactions on-chain.As an effective mitigation approach,the payment channel networks(PCNs)enable private channels among blockchain nodes to process transactions off-chain,relieving long-time waiting for the online transaction confirmation.The state-of-the-art studies of PCN focus on improving the efficiency and availability via optimizing routing,scheduling,and initial deposits,as well as preventing the system from security and privacy attacks.However,the behavioral decision dynamics of blockchain nodes under potential malicious attacks is largely neglected.To fill this gap,we employ the game theory to study the characteristics of channel interactions from both the micro and macro perspectives under the situation of channel depletion attacks.Our study is progressive,as we conduct the game-theoretic analysis of node behavioral characteristics from individuals to the whole population of PCN.Our analysis is complementary,since we utilize not only the classic game theory with the complete rationality assumption,but also the evolutionary game theory considering the limited rationality of players to portray the evolution of PCN.The results of numerous simulation experiments verify the effectiveness of our analysis.
基金supported by Blockchain@UBC,Natural Sciences and Engineering Research Council of Canada(RGPIN-2019-06348)National Natural Science Foundation of China(Project No.61902333)Shenzhen Institute of Artificial Intelligence and Robotics for Society(AIRS).
文摘Traditional centralized token exchange(CEX)has been suffering from hacking due to the centralized management of users’tokens.In contrast,decentralized token exchange(DEX)maintains users’assets by smart contracts in a decentralized manner,but introduces additional overhead in terms of gas fee and transaction confirmation latency.Hybrid decentralized token exchange(HEX)has been proposed to combine the benefits of CEX and DEX.However,existing HEX is criticized for two issues.First,trading transactions are time-consuming and expensive for frequent token traders.Second,excessive simultaneous transactions might cause the pending transaction congestion in the Ethereum network.In this paper,we propose a payment channel based HEX,which extends existing solutions by adding a new payment channel layer to benefit frequent traders and alleviate the pending transaction congestion.Besides,we propose the very first gas-price vs.transactionconfirmation-latency function to guide Ethereum transaction issuers to choose an optimal gas price that minimizes the overall cost.Extensive simulations are conducted to compare the cost in the proposed HEX with that in the conventional HEX.The results demonstrate the effectiveness of our proposed mechanism in terms of reducing gas fees and transaction confirmation latency for frequent traders as well as the pending transaction congestion in Ethereum.
基金This work is supported by the National Natural Science Foundation of China （No. 60473057, No. 90104026）, the National High Technology Research and Development Program of China （No. 2002AA144040）.
