TumbleBit: an untrusted Bitcoin-compatible anonymous payment hub
Files
Published version
Supporting documentation
Date
2017
Authors
Heilman, Ethan
AlShenibr, Leen
Baldimtsi, Foteini
Scafuro, Alessandra
Goldberg, Sharon
Version
Published version
OA Version
Citation
Ethan Heilman, Leen AlShenibr, Foteini Baldimtsi, Alessandra Scafuro, Sharon Goldberg. 2017. "TumbleBit: An Untrusted Bitcoin-Compatible Anonymous Payment Hub." Network and Distributed System Security Symposium.
Abstract
This paper presents TumbleBit, a new unidirectional unlinkable payment hub that is fully compatible with today s Bitcoin protocol. TumbleBit allows parties to make fast, anonymous, off-blockchain payments through an untrusted intermediary called the Tumbler. TumbleBits anonymity properties are similar to classic Chaumian eCash: no one, not even the Tumbler, can link a payment from its payer to its payee. Every payment made via TumbleBit is backed by bitcoins, and comes with a guarantee that Tumbler can neither violate anonymity, nor steal bitcoins, nor print money by issuing payments to itself. We prove the security of TumbleBit using the real/ideal world paradigm and the random oracle model. Security follows from the standard RSA assumption and ECDSA unforgeability. We implement TumbleBit, mix payments from 800 users and show that TumbleBits offblockchain payments can complete in seconds.