Title: Flexible Byzantine Fault Tolerance

Description: Speaker: Prof. Kartik Nayak

Time: Monday, 13 January 2020, 3:30pm
Venue: Department of Computer Science and Engineering, Room No. 109, 01st Floor, New CSE/CC Building

I will introduce Flexible BFT, a new approach for BFT consensus solution design revolving around two pillars, stronger resilience, and diversity. The first pillar, stronger resilience, involves a new fault model called alive-but-corrupt faults. Alive-but-corrupt replicas may arbitrarily deviate from the protocol in an attempt to break safety of the protocol. However, if they cannot break safety, they will not try to prevent liveness of the protocol. Combining alive-but-corrupt faults into the model, Flexible BFT is resilient to higher corruption levels than possible in a pure Byzantine fault model. The second pillar, diversity, designs consensus solutions whose protocol transcript is used to draw different commit decisions under diverse beliefs. With this separation, the same Flexible BFT solution supports synchronous and asynchronous beliefs, as well as varying resilience threshold combinations of Byzantine and alive-but-corrupt faults.

At a technical level, Flexible BFT achieves the above results using two new ideas. First, it introduces a synchronous BFT protocol in which only the commit step requires to know the network delay bound and thus replicas execute the protocol without any synchrony assumption. Second, it introduces a notion called Flexible Byzantine Quorums by dissecting the roles of different quorums in existing consensus protocols.

Speaker Profile:
Kartik Nayak is an assistant professor in the Department of Computer Science at Duke University. He works in the areas of security, applied cryptography, distributed computing, and blockchains. Before joining Duke University, he spent a year as a postdoctoral researcher at VMware Research. Before that, he graduated from the University of Maryland, College Park under the supervision of Professor Jonathan Katz and Professor Elaine Shi. Kartik is a recipient of the 2016 Google Ph.D. fellowship in Security.

Duke University

Prof. Manoj Prabhakaran

Date: Monday, 13 January, 2020
Time: 3:30pm IST
Access: Public
Category: Talk*
Created by: Department Calendar
Updated: Thursday, 1 April, 2021 9:85am IST
Send Reminder: Yes  -  165 hours 15 minutes before start
Participants: Department Calendar
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