SwapCT: Swap Confidential Transactions for Privacy-Preserving Multi-Token Exchanges

TY - GEN

T1 - SwapCT: Swap Confidential Transactions for Privacy-Preserving Multi-Token Exchanges

AU - Engelmann, Felix Theodor

AU - Müller, Lukas

AU - Peter, Andreas

AU - Kargl, Frank

AU - Bösch, Christoph

N1 - Conference code: 21

PY - 2021/7

Y1 - 2021/7

N2 - Decentralized token exchanges allow for secure trading of tokens without a trusted third party. However, decentralization is mostly achieved at the expense of transaction privacy. For a fair exchange, transactions must remain private to hide the participants and volumes while maintaining the possibility for noninteractive execution of trades. In this paper we present a swap confidential transaction system (SwapCT) which is related to ring confidential transactions (e.g. used in Monero) but supports multiple token types to trade among and enables secure, partial transactions for noninteractive swaps. We prove that SwapCT is secure in a strict, formal model and present its efficient performance in a prototype implementation with logarithmic signature sizes for large anonymity sets. For our construction we design an aggregatable signature scheme which might be of independent interest. Our SwapCT system thereby enables a secure and private exchange for tokens without a trusted third party.

AB - Decentralized token exchanges allow for secure trading of tokens without a trusted third party. However, decentralization is mostly achieved at the expense of transaction privacy. For a fair exchange, transactions must remain private to hide the participants and volumes while maintaining the possibility for noninteractive execution of trades. In this paper we present a swap confidential transaction system (SwapCT) which is related to ring confidential transactions (e.g. used in Monero) but supports multiple token types to trade among and enables secure, partial transactions for noninteractive swaps. We prove that SwapCT is secure in a strict, formal model and present its efficient performance in a prototype implementation with logarithmic signature sizes for large anonymity sets. For our construction we design an aggregatable signature scheme which might be of independent interest. Our SwapCT system thereby enables a secure and private exchange for tokens without a trusted third party.

KW - atomic swap

KW - typed tokens

KW - exchange

U2 - 10.2478/popets-2021-0070

DO - 10.2478/popets-2021-0070

M3 - Conference article

VL - 2021

SP - 270

EP - 290

JO - Proceedings on Privacy Enhancing Technologies

JF - Proceedings on Privacy Enhancing Technologies

IS - 4

T2 - Privacy Enhancing Technologies Symposium

Y2 - 12 July 2021 through 16 July 2021

ER -