Transaction Ordering

Related: Censorship

Ordering

Helix: A Scalable and Fair Consensus Algorithm Resistant to Ordering Manipulation

Avi Asayag, Gad Cohen, Ido Grayevsky, Maya Leshkowitz, Ori Rottenstreich, Ronen Tamari and David Yakira (Orbs)

ICNP'18

Based on threshold encryption and reputation

Enforcing Fairness in Blockchain Transaction Ordering

Ariel Orda and Ori Rottenstreich (Technion and Orbs)

ICBC'19

Order-Fairness for Byzantine Consensus

Mahimna Kelkar∗ Fan Zhang Steven Goldfeder Ari Juels (Cornell, IC3)

Crrypto'20

Permissioned setting

Order-Fair Consensus in the Permissionless Setting

Mahimna Kelkar and Soubhik Deb and Sreeram Kannan

See also: MEV Auction

Front-running

Flash Boys 2.0: Frontrunning, Transaction Reordering, and Consensus Instability in Decentralized Exchanges

Philip Daian, Steven Goldfeder Tyler Kell (Cornell), Yunqi Li (UIUC), Xueyuan Zhao (CMU), Iddo Bentov (Cornell Tech), Lorenz Breidenbach (ETH Zurich), Ari Juels (Cornell Tech)

S&P'20, Twitter thread

Observe DEX arbitrage bots engage in priority gas auctions (PGAs):

Competitively bidding up transaction fees in order to obtain priority ordering, i.e., early block position

Show that high fees paid for priority transaction ordering poses a systemic risk to consensus-layer security

Such fees are just one form of a general phenomenon in DEXes and beyond: miner extractable value (MEV)

SoK: Transparent Dishonesty: front-running attacks on Blockchain

Slide @DEVCON5

Solution

TEX – A Securely Scalable Trustless Exchange

Liquidity Network

Front-running resilient, non-custodial DEX

User submits a moonwalk order, which is time-locked w/ crypto puzzle, whose correctness is proved by ZKP

MMR-based commit-chain