Hiding transaction amounts and balances in Bitcoin

Elli Androulaki, Ghassan O. Karame

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Citations (Scopus)

Abstract

Bitcoin is gaining increasing adoption and popularity nowadays. In spite of its reliance on pseudonyms, Bitcoin raises a number of privacy concerns due to the fact that all of the transactions that take place in the system are publicly announced. The literature contains a number of proposals that aim at evaluating and enhancing user privacy in Bitcoin. To the best of our knowledge, ZeroCoin (ZC) is the first proposal which prevents the public tracing of coin expenditure in Bitcoin by leveraging zero-knowledge proofs of knowledge and one-way accumulators. While ZeroCoin hardens the traceability of coins, it does not hide the amount per transaction, nor does it prevent the leakage of the balances of Bitcoin addresses. In this paper, we propose, EZC, an extension of ZeroCoin which (i) enables the construction of multi-valued ZCs whose values are only known to the sender and recipient of the transaction and (ii) supports the expenditure of ZCs among users in the Bitcoin system, without the need to convert them back to Bitcoins. By doing so, EZC hides transaction values and address balances in Bitcoin, for those users who opt-out from exchanging their coins to BTCs. We performed a preliminary assessment of the performance of EZC; our findings suggest that EZC improves the communication overhead incurred in ZeroCoin.

Original languageEnglish
Title of host publicationTrust and Trustworthy Computing - 7th International Conference, TRUST 2014, Proceedings
PublisherSpringer Verlag
Pages161-178
Number of pages18
Volume8564 LNCS
ISBN (Print)9783319085920
DOIs
Publication statusPublished - 2014
Event7th International Conference on Trust and Trustworthy Computing, TRUST 2014 - Heraklion, Crete, Greece
Duration: 30 Jun 20142 Jul 2014

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume8564 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Other

Other7th International Conference on Trust and Trustworthy Computing, TRUST 2014
CountryGreece
CityHeraklion, Crete
Period30/06/142/07/14

Keywords

  • Bitcoin
  • hiding Bitcoin balances
  • hiding transaction amounts
  • user-privacy
  • ZeroCoin

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    Androulaki, E., & Karame, G. O. (2014). Hiding transaction amounts and balances in Bitcoin. In Trust and Trustworthy Computing - 7th International Conference, TRUST 2014, Proceedings (Vol. 8564 LNCS, pp. 161-178). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 8564 LNCS). Springer Verlag. https://doi.org/10.1007/978-3-319-08593-7_11