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2014 IEEE Symposium on Security and Privacy (SP) (2014)
Berkeley, CA, USA
May 18, 2014 to May 21, 2014
ISSN: 1081-6011
ISBN: 978-1-4799-4686-0
pp: 459-474
ABSTRACT
Bit coin is the first digital currency to see widespread adoption. While payments are conducted between pseudonyms, Bit coin cannot offer strong privacy guarantees: payment transactions are recorded in a public decentralized ledger, from which much information can be deduced. Zero coin (Miers et al., IEEE S&P 2013) tackles some of these privacy issues by unlinking transactions from the payment's origin. Yet, it still reveals payments' destinations and amounts, and is limited in functionality. In this paper, we construct a full-fledged ledger-based digital currency with strong privacy guarantees. Our results leverage recent advances in zero-knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARKs). First, we formulate and construct decentralized anonymous payment schemes (DAP schemes). A DAP scheme enables users to directly pay each other privately: the corresponding transaction hides the payment's origin, destination, and transferred amount. We provide formal definitions and proofs of the construction's security. Second, we build Zero cash, a practical instantiation of our DAP scheme construction. In Zero cash, transactions are less than 1 kB and take under 6 ms to verify - orders of magnitude more efficient than the less-anonymous Zero coin and competitive with plain Bit coin.
INDEX TERMS
Online banking, Privacy, Public key, Protocols, Logic gates,zero knowledge, Bitcoin, decentralized electronic cash
CITATION
"Zerocash: Decentralized Anonymous Payments from Bitcoin", 2014 IEEE Symposium on Security and Privacy (SP), vol. 00, no. , pp. 459-474, 2014, doi:10.1109/SP.2014.36
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