Bitcoin has made an increasing impact on the world's economy and financial order,which attracted extensive attention of researchers and regulators from all over the world.Most previous studies had focused more on ...Bitcoin has made an increasing impact on the world's economy and financial order,which attracted extensive attention of researchers and regulators from all over the world.Most previous studies had focused more on the transaction layer,but less on the network layer.In this paper,we developed BNS(Bitcoin Network Sniffer),which could find and connect nodes in the Bitcoin network,and made a measurement in detail.We collected nearly 4.1 million nodes in 1.5 hours and identified 9,515 reachable nodes.We counted the reachable nodes'properties such as:service type,port number,client version and geographic distribution.In addition,we analyzed the stability of the reachable nodes in depth and found nearly 60%kept stable during 15 days.Finally,we proposed a new approach to infer the Bitcoin network topology by analyzing the Neighbor Addresses of Adjacent Nodes and their timestamps,which had an accuracy over 80%.展开更多
Bitcoin is a digital currency based on a peer-to-peer network to propagate and verify transactions.Bitcoin is gaining wider adoption than any previous crypto-currency.However,the mechanism of peers randomly choosing l...Bitcoin is a digital currency based on a peer-to-peer network to propagate and verify transactions.Bitcoin is gaining wider adoption than any previous crypto-currency.However,the mechanism of peers randomly choosing logical neighbours without any knowledge about the underlying physical topology can cause a delay overhead in information propagation which makes the system vulnerable to double spend attacks.Aiming at alleviating the propagation delay problem,this paper introduces a proximity-aware extension to the current Bitcoin protocol,named Master Node Based Clustering(MNBC).The ultimate purpose of the proposed protocol,which is based on how clusters are formulated and how nodes can define their membership,is to improve the information propagation delay in the Bitcoin network.In the MNBC protocol,physical internet connectivity increases as well as the number of hops between nodes decreases through assigning nodes to be responsible for maintaining clusters based on physical Internet proximity.Furthermore,a reputation-based blockchain protocol is integrated with MNBC protocol in order to securely assign a master node for every cluster.We validate our proposed methods through a set of simulation experiments and the findings show how the proposed methods run and their impact in optimising the transaction propagation delay.展开更多
自私挖矿攻击是一种挖矿策略,存在基于工作量证明(PoW,proof of work)机制的区块链中。自私矿工通过延迟区块广播的时机来截取其他矿工的挖矿奖励,以此获得比正常情况下更多的收益。这种攻击对工作量证明机制的激励相容性造成了破坏。...自私挖矿攻击是一种挖矿策略,存在基于工作量证明(PoW,proof of work)机制的区块链中。自私矿工通过延迟区块广播的时机来截取其他矿工的挖矿奖励,以此获得比正常情况下更多的收益。这种攻击对工作量证明机制的激励相容性造成了破坏。近年来,自私挖矿这一攻击行为被研究者从许多角度进行了研究和分析。然而这一挖矿策略利用了工作量证明机制区块链在网络延迟方面存在的缺陷,使得采用这一挖矿策略的矿工在行为上与正常挖矿行为没有明显的区别,导致当前缺少可以有效检测出自私挖矿行为的方案。因此,提出了一种自私挖矿的检测方案,该检测方案创新性地利用了区块链中区块的高度和区块中的交易记录特征,可以做到对网络中的自私挖矿行为进行实时检测,有一定的实用价值。所提检测方案为生成的新区块定义了一个状态值,这个状态值与区块中包含的交易数量、支付给矿工的交易费用等数据有关。根据这些特征值间的数学关系,可以判断出该区块是否来自自私矿工。通过仿真实验测试了攻击者在不同算力下,该检测方案的检测情况。结果表明,所提检测方案在判断区块是否来自自私挖矿时,有86.02%以上的检测准确率,可以有效地对自私挖矿产生的区块进行检测。展开更多
基金supported by National Key Research and Development Program of China (Grant No.2020YFB1006105)
文摘Bitcoin has made an increasing impact on the world's economy and financial order,which attracted extensive attention of researchers and regulators from all over the world.Most previous studies had focused more on the transaction layer,but less on the network layer.In this paper,we developed BNS(Bitcoin Network Sniffer),which could find and connect nodes in the Bitcoin network,and made a measurement in detail.We collected nearly 4.1 million nodes in 1.5 hours and identified 9,515 reachable nodes.We counted the reachable nodes'properties such as:service type,port number,client version and geographic distribution.In addition,we analyzed the stability of the reachable nodes in depth and found nearly 60%kept stable during 15 days.Finally,we proposed a new approach to infer the Bitcoin network topology by analyzing the Neighbor Addresses of Adjacent Nodes and their timestamps,which had an accuracy over 80%.
文摘Bitcoin is a digital currency based on a peer-to-peer network to propagate and verify transactions.Bitcoin is gaining wider adoption than any previous crypto-currency.However,the mechanism of peers randomly choosing logical neighbours without any knowledge about the underlying physical topology can cause a delay overhead in information propagation which makes the system vulnerable to double spend attacks.Aiming at alleviating the propagation delay problem,this paper introduces a proximity-aware extension to the current Bitcoin protocol,named Master Node Based Clustering(MNBC).The ultimate purpose of the proposed protocol,which is based on how clusters are formulated and how nodes can define their membership,is to improve the information propagation delay in the Bitcoin network.In the MNBC protocol,physical internet connectivity increases as well as the number of hops between nodes decreases through assigning nodes to be responsible for maintaining clusters based on physical Internet proximity.Furthermore,a reputation-based blockchain protocol is integrated with MNBC protocol in order to securely assign a master node for every cluster.We validate our proposed methods through a set of simulation experiments and the findings show how the proposed methods run and their impact in optimising the transaction propagation delay.
文摘自私挖矿攻击是一种挖矿策略,存在基于工作量证明(PoW,proof of work)机制的区块链中。自私矿工通过延迟区块广播的时机来截取其他矿工的挖矿奖励,以此获得比正常情况下更多的收益。这种攻击对工作量证明机制的激励相容性造成了破坏。近年来,自私挖矿这一攻击行为被研究者从许多角度进行了研究和分析。然而这一挖矿策略利用了工作量证明机制区块链在网络延迟方面存在的缺陷,使得采用这一挖矿策略的矿工在行为上与正常挖矿行为没有明显的区别,导致当前缺少可以有效检测出自私挖矿行为的方案。因此,提出了一种自私挖矿的检测方案,该检测方案创新性地利用了区块链中区块的高度和区块中的交易记录特征,可以做到对网络中的自私挖矿行为进行实时检测,有一定的实用价值。所提检测方案为生成的新区块定义了一个状态值,这个状态值与区块中包含的交易数量、支付给矿工的交易费用等数据有关。根据这些特征值间的数学关系,可以判断出该区块是否来自自私矿工。通过仿真实验测试了攻击者在不同算力下,该检测方案的检测情况。结果表明,所提检测方案在判断区块是否来自自私挖矿时,有86.02%以上的检测准确率,可以有效地对自私挖矿产生的区块进行检测。
