Priority queueing analysis of transaction-confirmation time for Bitcoin
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Abstract
In Bitcoin system, a transaction is given a priority value according to its attributes such as the remittance amount and fee, and transactions with high priorities are likely to be confirmed faster than those with low priorities. In this paper, we analyze the transaction-confirmation time for Bitcoin system. We model the transaction-confirmation process as a queueing system with batch service, M/$ \mbox{G}^B $/1. We consider the joint distribution of numbers of transactions in system and the elapsed service time, deriving the mean transaction-confirmation time. Using the result, we derive the recursive formulae of mean transaction-confirmation times of an M/$ \mbox{G}^B $/1 queue with priority service discipline. In numerical examples, we show the effect of the maximum block size on the mean transaction-confirmation time, investigating the accuracy region of our queueing model. We also discuss how the increase in micropayments, which are likely to be given low priorities, affects the transaction-confirmation time.
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Keywords:
- Bitcoin,
- blockchain,
- transaction-confirmation time,
- priority queue.
Mathematics Subject Classification: Primary: 68M20, 90B22; Secondary: 60K25.Citation: -
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Table 1. Mean transaction confirmation time for each priority
Period Classless [s] Low priority [s] High priority [s] 1st (2013/10/1-2014/9/30) 1060.67797 1947.47115 1044.25043 2nd (2014/10/1-2015/9/30) 1171.98866 4887.56496 1070.32818 overall (2013/10/1-2015/9/30) 1124.13286 3888.06977 1059.06133 Table 2. Comparison of analysis and measurement
Transaction Type Arrival Rate Measurement [s] Analysis[s] Classless 0.9709120529 1124.13286 1112.025339 High Priority 0.9349109906 1059.06133 1108.773595 Low Priority 0.0360010622 3888.06977 1196.469817 Table 3. Coefficients of variation for transaction interarrival time
Period 1st
2013/10-2014/092nd
2014/10-2015/09Overall
2013/10-2015/09Classless 3.72401 15.32505 10.17893 Table 4. Coefficients of variation for transaction interarrival time, two-priority classes
Period 1st
2013/10-2014/092nd
2014/10-2015/09Overall
2013/10-2015/09Low Priority 1.66569 3.90654 3.01387 High Priority 3.70045 14.94895 9.99103 -
References
[1] A. M. Antonopoulos, Mastering Bitcoin, O'Reilly, 2014. [2] M. L. Chaudhry and J. G. C. Templeton, The queuing system M/GB/1 and its ramifications, European Journal of Operational Research, 6 (1981), 56-60. doi: 10.1016/0377-2217(81)90328-3. [3] M. L. Chaudhry and J. G. C. Templeton, A First Course in Bulk Queues, John Wiley & Sons, 1983. [4] http://www.meti.go.jp/committee/kenkyukai/sansei/fintech\_kadai/pdf/003\_02\_00.pdf [5] http://www.coindesk.com/1mb-block-size-today-bitcoin/ [6] https://blockchain.info/ [7] http://www.coindesk.com/segregated-witness-bitcoin-block-size-debate/ [8] S. Kasahara and J. Kawahara, Effect of Bitcoin fee on transaction-confirmation process, arXiv: 1604.00103[cs.CR]. [9] Y. Kawase and S. Kasahara, Transaction-Confirmation Time for Bitcoin: A Queueing Analytical Approach to Blockchain Mechanism, The 12th International Conference on Queueing Theory and Network Applications (QTNA2017), Qinhuangdao, China, August 21-23, 2017. [10] M. Möser and R. Böhome, Trends, tips, tolls: A longitudinal study of bitcoin transaction fees, Financial Cryptography and Data Security, Lecture Notes in Computer Science, Springer, 8976 (2015), 19-33. doi: 10.1007/978-3-662-48051-9_2. [11] S. Nakamoto, Bitcoin: A Peer-to-Peer Electronic Cash System, 2008. Available from: https://bitcoin.org/bitcoin.pdf. [12] J. Poon and T. Dryja, The bitcoin lightning network: Scalable off-chain instant payments, https://lightning.network/lightning-network-paper.pdf, 2016. [13] H. Takagi, Queueing Analysis: A Foundation of Performance Evaluation, Vol. 2. Finite systems. North-Holland Publishing Co., Amsterdam, 1993. [14] https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki [15] F. Tschorsch and B. Scheuermann, Bitcoin and beyond: A technical survey on decentralized digital currencies, Tutorials, 18 (2016), 2084-2123. [16] https://www.bitcoincash.org/ [17] https://www.coindesk.com/segwits-slow-rollout-bitcoins-capacity-hasnt-seen/ -
Access History
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Figure 1.
Comparison of analysis and simulation for basic queueing model
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Figure 2.
Comparison of analysis and simulation for priority-queueing model
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Figure 3.
Transaction-confirmation time vs. block size, 1st period (October 2013 to September 2014).
,$ \lambda = 0.7336929 $ , and the coefficient of variation of transaction inter-arrival time:$ \mu = 0.0019748858 $ $ 3.72401599 $ -
Figure 4.
Transaction-confirmation time vs. block size, 2nd period (October 2014 to September 2015).
,$ \lambda = 1.2081311 $ , and the coefficient of variation of transaction inter-arrival time:$ \mu = 0.0017009449 $ $ 15.3250509 $ -
Figure 5.
The mean transaction-arrival rate
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Figure 6.
Transaction-confirmation time vs. block size, October 2013 to September 2014.
,$ \lambda_H = 0.7203544 $ $ \mu = 0.0019748858 $ -
Figure 7.
Transaction-confirmation time vs. block size, October 2014 to September 2015.
,$ \lambda_H = 1.1494675 $ $ \mu = 0.0017009449 $ -
Figure 8.
Transaction-confirmation time vs. block size, October 2013 to September 2014.
,$ \lambda_L = 0.0133385 $ $ \mu = 0.0019748858 $ -
Figure 9.
Transaction-confirmation time vs. block size, October 2014 to September 2015.
,$ \lambda_L = 0.0586636 $ $ \mu = 0.0017009449 $ -
Figure 10.
The effects of the block size on the transaction-confirmation time
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Figure 11.
The effects of the micropayments on the transaction-confirmation time
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Figure 12.
The effect of the block size on the transaction-confirmation time of high-priority transactions
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Figure 13.
The effects of the block size on the transaction-confirmation time of low-priority transactions