In this work, we question the necessity of a privacy-invasive transaction ledger. In particular, we present SilentWhispers, the first distributed, privacy-preserving credit network that does not require any ledger to protect the integrity of transactions. Yet, SilentWhispers guarantees integrity and privacy of link values and transactions even in the presence of distrustful users and malicious neighbors, whose misbehavior in changing link values is detected and such users can be held accountable. We formalize these properties as ideal functionalities in the universal composability framework and present a secure realization based on a novel combination of secret-sharing-based multiparty computation and digital signature chains. SilentWhispers can handle network churn, and it is efficient as demonstrated with a prototype implementation evaluated using payments data extracted from the currently deployed Ripple payment system.
Category / Keywords: decentralized credit networks, Ripple, privacy-preserving transactions Original Publication (with major differences): NDSS 2017 Date: received 9 Nov 2016 Contact author: pmorenos at purdue edu Available format(s): PDF | BibTeX Citation Version: 20161115:144943 (All versions of this report) Short URL: ia.cr/2016/1054 Discussion forum: Show discussion | Start new discussion