TY - GEN
T1 - Zether
T2 - 24th International Conference on Financial Cryptography and Data Security, FC 2020
AU - Bünz, Benedikt
AU - Agrawal, Shashank
AU - Zamani, Mahdi
AU - Boneh, Dan
N1 - Publisher Copyright:
© 2020, International Financial Cryptography Association.
PY - 2020
Y1 - 2020
N2 - Smart contract platforms such as Ethereum and Libra provide ways to seamlessly remove trust and add transparency to various distributed applications. Yet, these platforms lack mechanisms to guarantee user privacy, even at the level of simple payments, which are essential for most smart contracts. In this paper, we propose Zether, a trustless mechanism for privacy-preserving payments in smart contract platforms. We take an account-based approach similar to Ethereum and Libra for efficiency and usability. Zether is implemented as a smart contract that keeps account balances encrypted and exposes methods to deposit, transfer, and withdraw funds to/from accounts through cryptographic proofs at only a small cost. We address several technical challenges to protect Zether against replay attacks and front-running situations and develop a mechanism to enable interoperability with arbitrary smart contracts, making applications like auctions, payment channels, and voting privacy-preserving. To make Zether efficient, we propose-Bullets, a zero-knowledge proof system that is optimized for-protocols. We implement Zether as an Ethereum smart contract and show its practicality by measuring the amount of gas used by the Zether contract. A Zether confidential transaction costs about 0.014 ETH or approximately $1.51 (as of early 2019), which can be drastically reduced with minor changes to Ethereum that we describe in the paper.
AB - Smart contract platforms such as Ethereum and Libra provide ways to seamlessly remove trust and add transparency to various distributed applications. Yet, these platforms lack mechanisms to guarantee user privacy, even at the level of simple payments, which are essential for most smart contracts. In this paper, we propose Zether, a trustless mechanism for privacy-preserving payments in smart contract platforms. We take an account-based approach similar to Ethereum and Libra for efficiency and usability. Zether is implemented as a smart contract that keeps account balances encrypted and exposes methods to deposit, transfer, and withdraw funds to/from accounts through cryptographic proofs at only a small cost. We address several technical challenges to protect Zether against replay attacks and front-running situations and develop a mechanism to enable interoperability with arbitrary smart contracts, making applications like auctions, payment channels, and voting privacy-preserving. To make Zether efficient, we propose-Bullets, a zero-knowledge proof system that is optimized for-protocols. We implement Zether as an Ethereum smart contract and show its practicality by measuring the amount of gas used by the Zether contract. A Zether confidential transaction costs about 0.014 ETH or approximately $1.51 (as of early 2019), which can be drastically reduced with minor changes to Ethereum that we describe in the paper.
UR - http://www.scopus.com/inward/record.url?scp=85089218798&partnerID=8YFLogxK
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U2 - 10.1007/978-3-030-51280-4_23
DO - 10.1007/978-3-030-51280-4_23
M3 - Conference contribution
AN - SCOPUS:85089218798
SN - 9783030512798
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 423
EP - 443
BT - Financial Cryptography and Data Security - 24th International Conference, FC 2020, Revised Selected Papers
A2 - Bonneau, Joseph
A2 - Heninger, Nadia
PB - Springer
Y2 - 10 February 2020 through 14 February 2020
ER -