Order-Fair Consensus

Speaker: Mahimna Kelkar

Title: Order-Fair Consensus

Abstract: Decades of research in both cryptography and distributed systems has extensively studied the problem of state machine replication or Byzantine consensus. A consensus protocol must satisfy two properties: consistency and liveness. These properties ensure that honest participating nodes agree on the same transaction log and dictate when fresh transactions get added. They fail, however, to ensure against adversarial manipulation of the actual ordering of transactions in the log. This is especially problematic in the emerging area of decentralized finance where attackers have been shown to extract profits by manipulating the transaction ordering.

In this talk, I will introduce our recent line of work on order-fair consensus, which proposes a third consensus property: transaction order-fairness. Order-fairness imposes strong ordering guarantees on the transactions in the log in order to provide better protection against order-manipulation attacks.

This talk is based on the works ia.cr/2020/269, ia.cr/2021/139 and ia.cr/2021/1465 with co-authors Soubhik Deb, Steven Goldfeder, Ari Juels, Sreeram Kannan, Sishan Long, and Fan Zhang. 

Speaker Bio: Mahimna Kelkar is a PhD student at Cornell University advised by Ari Juels. His research interests are broadly in theoretical and applied cryptography with particular emphasis on blockchains.