Abstract: This talk gives a glimpse onto a decade of innovation which has been sparked by blockchains in scaling BFT Consensus. In a nutshell, a Consensus system allows a network of nodes to act in coordinated manner despite both benign outages and security (“Byzantine”) threats. For over four decades, experts in the field have been looking for Consensus solutions that can perform well in practice. In 2018, HotStuff transformed the landscape of practical BFT consensus solutions by introducing two key contributions, linearity and streamlining: HotStuff is the first BFT protocol that achieves linear communication complexity even when a fault occurs. Additionally, the HotStuff protocol is modular, consisting of a recurring broadcast module that can be pipelined, such that each broadcast extends the sequence of decisions by one. HotStuff was adopted by the famous Diem(Libra) project to drive global payment rails backed by a consortium-operated blockchain. In the end, Diem did not launch, but the technology behind it illuminated and fertilized the field.  The talk overviews solutions enabled by HotStuff to open problems which emerged under a variety of settings, underscoring insights from the blockchain arena that led to new approaches.

Bio: 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 serves as Distinguished Scientist of Chainlink Labs  since 2022. 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.