Professor Dahlia Malkhi, UC Santa Barbara

University of California, Santa Barbara


From Libra to Space: Research Advances in Scaling Byzantine Consensus

Time & Venue

Abstract

This talk presents a journey of the HotStuff from its inception to space.
Being able to scale quorum-based consensus drove years of research. HotStuff is a Byzantine consensus algorithm that introduces linear communication for the first time. Instead of complex protocols with multiple communication-heavy steps to confirm a block, HotStuff has a linear, uniform pattern that makes consensus faster and scalable for thousands of nodes. HotStuff meteoric adoption was foretold by DiemBFT the first large-scale HotStuff implementation by the Facebook Libra(Diem), with Professor Malkhi as CTO, which sought to be a regulatory-friendly financial system. Although Diem never launched, its technology had a big impact on the industry. DiemBFT now powers the Aptos blockchain, Cypherium, Flow, Celo, Espresso Systems, and Pocket Network, as their core consensus engines. Many improvements were made on the original HotStuff: latency (eg, HotStuff-2, HotStuff-1), throughput (eg, Lumiere, Narwhal-HS), assumptions (eg, Sync HotStuff, Information Theoretic HotStuff, Flexible BFT) and resilience against threats (eg, Strengthened HotStuff, Today, SpaceComputer.IO employs HotShot, a production-grade HotStuff variant, to create a network of tamper-proof satellites.

Biography


Dahlia Malkhi is a Professor in the Department of Computer Science of UCSB since 2024. She heads the Foundations of Financial Technology lab. Her research over two decades spans broad aspects of reliability and security of distributed systems, recently with focus on blockchains and advances in financial technology. Her work resulted in over 200 publications as well as a strong impact on computing technology.
Malkhi is sought-after industrial consultant, currently advising various projects, including Space Computer, Lyquor Labs, Nubit|Bitcoin Thunderbolt, Espresso Systems, and Chainlink Labs. Formerly, she served as Distinguished Scientist of Chainlink Labs (2022-2025). From 2019 to 2022, she was the CTO at the Diem Association , and Lead Researcher at Novi Financial . In 2014, she co-founded VMware Research and became a Principal Researcher at VMware until 2019. Prior to that, Malkhi was a partner principal researcher at Microsoft Research, 2004-2014; an Associate Professor of the Hebrew University of Jerusalem, and a senior researcher at AT&T Labs.