Wendy, the Good Little Fairness Widget

Klaus Kursawe

Paper 2020/885

Wendy, the Good Little Fairness Widget

Klaus Kursawe

Abstract

The advent of decentralized trading markets introduces a number of new challenges for consensus protocols. In addition to the 'usual' attacks - a subset of the validators trying to prevent disagreement -- there is now the possibility of financial fraud, which can abuse properties not normally considered critical in consensus protocols. We investigate the issues of attackers manipulating or exploiting the order in which transactions are scheduled in the blockchain. More concretely, we look into relative order fairness, i.e., ways we can assure that the relative order of transactions is fair. We show that one of the more intuitive definitions of fairness is impossible to achieve. We then present Wendy, a group of low overhead protocols that can implement different concepts of fairness. Wendy acts as an aditional widget for an existing blockchain, and is largely agnostic to the underlying blockchain and its security assumptions. Furthermore, it is possible to apply a the protocol only for a subset of the transactions, and thus run several independent fair markets on the same chain.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint. MINOR revision.
Keywords: Blockchain Byzantine Fault Tolerance Frontrunning
Contact author(s): klaus @ vega xyz
History: 2020-07-16: received
Short URL: https://ia.cr/2020/885
License: CC BY

BibTeX

@misc{cryptoeprint:2020/885,
      author = {Klaus Kursawe},
      title = {Wendy, the Good Little Fairness Widget},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/885},
      year = {2020},
      url = {https://eprint.iacr.org/2020/885}
}