Abstract
Mixcoin is a Bitcoin mixing protocol proposed by Bonneau et al. which provides strong accountability guarantees [13]. However, in the Mixcoin protocol, the mapping from a user’s input to output address is visible to the mixing server. We modify the Mixcoin protocol to provide guarantees that the input/output address mapping for any user is kept hidden from the mixing server. In order to achieve this, we make use of a blind signature scheme [14, 23] as well as an append-only public log. The scheme is fully compatible with Bitcoin, forces mixes to be accountable, preserves user anonymity even against a malicious mix, is resilient to denial of service attacks, and easily scales to many users.
B. Rowan—This work originated as a project in a computer networks course at the University of Maryland.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
References
Bitcoin fog. http://www.bitcoinfog.com/
Bitlaundry. http://app.bitlaundry.com/
Bitmixer.io. https://bitmixer.io/
The current state of coin-mixing services. http://www.thebitcoinreview.com/site.php?site_id=759
Online anonymity is not only for trolls and political dissidents. https://www.eff.org/deeplinks/2013/10/online-anonymity-not-only-trolls-and-political-dissidents
Bitcoin message service, October 2011. https://bitcointalk.org/index.php?topic=47283.0
Coinswap, October 2013. https://bitcointalk.org/index.php?topic=321228
blockchain.info, October 2014. https://blockchain.info/
Transaction fees, March 2014. https://en.bitcoin.it/wiki/Transaction_fees
Androulaki, E., Karame, G.O., Roeschlin, M., Scherer, T., Capkun, S.: Evaluating user privacy in bitcoin. In: Sadeghi, A.-R. (ed.) FC 2013. LNCS, vol. 7859, pp. 34–51. Springer, Heidelberg (2013)
Barber, S., Boyen, X., Shi, E., Uzun, E.: Bitter to better — how to make bitcoin a better currency. In: Keromytis, A.D. (ed.) FC 2012. LNCS, vol. 7397, pp. 399–414. Springer, Heidelberg (2012)
Ben-Sasson, E., Chiesa, A., Garman, C., Green, M., Miers, I., Tromer, E., Virza, M.: Zerocash: decentralized anonymous payments from bitcoin. In: 2014 IEEE Symposium on Security and Privacy (SP). IEEE (2014)
Bonneau, J., Narayanan, A., Miller, A., Clark, J., Kroll, J.A., Felten, E.W.: Mixcoin: anonymity for bitcoin with accountable mixes. IACR Cryptology ePrint Archive, 2014:77 (2014)
Chaum, D.: Blind signatures for untraceable payments. In: Chaum, D., Rivest, R.L., Sherman, A.T. (eds.) Advances in Cryptology, pp. 199–203. Springer, Heidelberg (1983)
Chaum, D.L.: Untraceable electronic mail, return addresses, and digital pseudonyms. Commun. ACM 24(2), 84–90 (1981)
Clark, J., Hengartner, U.: On the use of financial data as a random beacon. IACR Cryptology ePrint Archive, 2010:361 (2010)
Dingledine, R., Mathewson, N.: Anonymity loves company: usability and the network effect. In: WEIS (2006)
Dingledine, R., Mathewson, N., Syverson, P.: Tor: The second-generation onion router. Technical report, DTIC Document (2004)
Douceur, J.R.: The sybil attack. In: Druschel, P., Kaashoek, M.F., Rowstron, A. (eds.) IPTPS 2002. LNCS, vol. 2429, pp. 251–260. Springer, Heidelberg (2002)
Doyle, T., Veranas, J.: Public anonymity and the connected world. Ethics Inf. Technol. 16(3), 207–218 (2014)
Fischlin, M.: Round-optimal composable blind signatures in the common reference string model. In: Dwork, C. (ed.) CRYPTO 2006. LNCS, vol. 4117, pp. 60–77. Springer, Heidelberg (2006)
Fleder, M., Kester, M.S., Pillai, S.: Bitcoin transaction graph analysis (2014). http://people.csail.mit.edu/spillai/data/papers/bitcoin-transaction-graph-analysis.pdf
Fuchsbauer, G.: Automorphic signatures in bilinear groups and an application to round-optimal blind signatures. IACR Cryptology ePrint Archive, 2009:320 (2009)
Maxwell, G.: Coinjoin: Bitcoin privacy for the real world, August 2013. https://bitcointalk.org/index.php?topic=279249
Miers, I., Garman, C., Green, M., Rubin, A.D.: Zerocoin: anonymous distributed e-cash from bitcoin. In: 2013 IEEE Symposium on Security and Privacy (SP), pp. 397–411. IEEE (2013)
Möser, M., Bohme, R., Breuker, D.: An inquiry into money laundering tools in the bitcoin ecosystem. In: eCrime Researchers Summit (eCRS), pp. 1–14. IEEE (2013)
Nakamoto, S.: Bitcoin: a peer-to-peer electronic cash system. Consulted 1(2012), 28 (2008)
Ober, M., Katzenbeisser, S., Hamacher, K.: Structure and anonymity of the bitcoin transaction graph. Future Internet 5(2), 237–250 (2013)
Palme, J., Berglund, M.: Anonymity on the internet. Accessed 15 August 2009 (2002)
Reid, F., Harrigan, M.: An analysis of anonymity in the bitcoin system. In: Altshuler, Y., Elovici, Y., Cremers, A.B., Aharony, N., Pentland, A. (eds.) Security and Privacy in Social Networks. Springer, Heidelberg (2013)
Ron, D., Shamir, A.: Quantitative analysis of the full bitcoin transaction graph. In: Sadeghi, A.-R. (ed.) FC 2013. LNCS, vol. 7859, pp. 6–24. Springer, Heidelberg (2013)
Ruffing, T., Moreno-Sanchez, P., Kate, A.: Practical decentralized coin mixing for bitcoin. HotPETS, Coinshuffle, July 2014
Sweeney, L.: k-anonymity: a model for protecting privacy. Int. J. Uncertainty Fuzziness Knowl.-Based Syst. 10(05), 557–570 (2002)
Yang, E.Z.: Secure multiparty bitcoin anonymization, July 2013. http://blog.ezyang.com/2012/07/secure-multiparty-bitcoin-anonymization/
Acknowledgements
We would like to thank the anonymous reviewers, as well as Nadia Heninger, Andrew Miller, Dave Levin, and Bobby Bhattacharjee for their helpful comments and input.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2015 International Financial Cryptography Association
About this paper
Cite this paper
Valenta, L., Rowan, B. (2015). Blindcoin: Blinded, Accountable Mixes for Bitcoin. In: Brenner, M., Christin, N., Johnson, B., Rohloff, K. (eds) Financial Cryptography and Data Security. FC 2015. Lecture Notes in Computer Science(), vol 8976. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-48051-9_9
Download citation
DOI: https://doi.org/10.1007/978-3-662-48051-9_9
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-48050-2
Online ISBN: 978-3-662-48051-9
eBook Packages: Computer ScienceComputer Science (R0)