Imperial College London
Alternate

ProfessorWilliamKnottenbelt

Faculty of Engineering, Department of Computing

Professor of Applied Quantitative Analysis
 
 
 
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Contact

 

+44 (0)20 7594 8331w.knottenbelt Website

 
 
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Location

 

E363ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Zamyatin:2020,
author = {Zamyatin, A and Avarikioti, Z and Perez, D and Knottenbelt, WJ},
publisher = {Cryptology ePrint Archive},
title = {TxChain: efficient cyptocurrency light clients via contingent transaction aggregation.},
url = {https://eprint.iacr.org/2020/580.pdf},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - UNPB
AB  - Cryptocurrency light- or simplified payment verification (SPV) clientsallow nodes with limited resources to efficiently verify execution of payments.Instead of downloading the entire blockchain, only block headers and selectedtransactions are stored. Still, the storage and bandwidth cost, linear in blockchainsize, remain non-negligible, especially for smart contracts and mobile devices: asof April 2020, these amount to 50 MB in Bitcoin and 5 GB in Ethereum.Recently, two improved sublinear light clients were proposed: to validate theblockchain, NIPoPoWs and FlyClient only download a polylogarithmic numberof block headers, sampled at random. The actual verification of payments, however, remains costly: for each verified transaction, the corresponding block musttoo be downloaded. This yields NIPoPoWs and FlyClient only effective underlow transaction volumes.We present TXCHAIN, a novel mechanism to maintain efficiency of light clientseven under high transaction volumes. Specifically, we introduce the concept ofcontingent transaction aggregation, where proving inclusion of a single contingent transaction implicitly proves that n other transactions exist in the blockchain.To verify n payments, TXCHAIN requires a only single transaction in the best(n ≤ c), and dnc + logc(n)e transactions in the worst case (n > c). We deployTXCHAIN on Bitcoin without consensus changes and implement a soft fork forEthereum. To demonstrate effectiveness in the cross-chain setting, we implementTXCHAIN as a smart contract on Ethereum to efficiently verify Bitcoin payments.
AU  - Zamyatin,A
AU  - Avarikioti,Z
AU  - Perez,D
AU  - Knottenbelt,WJ
PB  - Cryptology ePrint Archive
PY  - 2020///
TI  - TxChain: efficient cyptocurrency light clients via contingent transaction aggregation.
UR  - https://eprint.iacr.org/2020/580.pdf
UR  - http://hdl.handle.net/10044/1/80199
ER  -
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