Professor Gregory Chockler
Academic and research departments
Distributed and Networked Systems Group, Surrey Centre for Cyber Security, Department of Computer Science.About
Biography
I am a Professor at the Department of Computer Science, University of Surrey, UK, where I am Joint Head of the Distributed and Networked Systems group and a member of the Surrey Centre for Cyber Security.
I joined University of Surrey in January 2020 as a Full Professor. From 2012 and until January 2020, I served as a tenured faculty at Royal Holloway, University of London starting as an Associate Professor (Reader), and being promoted to Full Professor in 2017. Between 2005 and 2012, I was a Research Staff Member at IBM Research. From 2003-2005, I was a Postdoctoral Associate with the MIT Computer Science and Artificial Intelligence Laboratory. I have held visiting scientist positions at EPFL, KTH, SICS, Emory University, IBM, and IMDEA Software Institute.
Areas of specialism
ResearchResearch interests
My research interests span both fundamental and applied aspects of fault-tolerance and trustworthiness of distributed systems. While at IBM, I co-invented and participated in the development of a new event-monitoring technology, which incorporated concepts from random graph theory and weak consistency, to boost scalability of the control planes of IBM WebSphere line of products (notably WebSphere Virtual Enterprise), by several orders of magnitude. I also co-invented Speculative Paxos, a new reconfigurable replication protocol, which was integrated into the management tiers of several IBM cloud offerings (notably, IBM WebSphere Liberty and PureApp) to improve their availability and failure resilience. For this work, I received several corporate-level awards including two Outstanding Technical Achievement Awards and a Scientific Accomplishment Award. My recent work focuses on blockchain and scalable information diffusion and is funded by the Stellar Development Foundation Academic Research Grant (October 2020), IBM Shared University Research Award (2017) and Facebook Faculty Award (2015).
Research interests
My research interests span both fundamental and applied aspects of fault-tolerance and trustworthiness of distributed systems. While at IBM, I co-invented and participated in the development of a new event-monitoring technology, which incorporated concepts from random graph theory and weak consistency, to boost scalability of the control planes of IBM WebSphere line of products (notably WebSphere Virtual Enterprise), by several orders of magnitude. I also co-invented Speculative Paxos, a new reconfigurable replication protocol, which was integrated into the management tiers of several IBM cloud offerings (notably, IBM WebSphere Liberty and PureApp) to improve their availability and failure resilience. For this work, I received several corporate-level awards including two Outstanding Technical Achievement Awards and a Scientific Accomplishment Award. My recent work focuses on blockchain and scalable information diffusion and is funded by the Stellar Development Foundation Academic Research Grant (October 2020), IBM Shared University Research Award (2017) and Facebook Faculty Award (2015).
Supervision
Postgraduate research supervision
Publications
Partially synchronous Byzantine consensus protocols typically structure their execution into a sequence of views, each with a designated leader process. The key to guaranteeing liveness in these protocols is to ensure that all correct processes eventually overlap in a view with a correct leader for long enough to reach a decision. We propose a simple view synchronizer abstraction that encapsulates the corresponding functionality for Byzantine consensus protocols, thus simplifying their design. We present a formal specification of a view synchronizer and its implementation under partial synchrony, which runs in bounded space despite tolerating message loss during asynchronous periods. We show that our synchronizer specification is strong enough to guarantee liveness for single-shot versions of several well-known Byzantine consensus protocols, including PBFT and HotStuff. We furthermore give precise latency bounds for these protocols when using our synchronizer. By factoring out the functionality of view synchronization we are able to specify and analyze the protocols in a uniform framework, which allows comparing them and highlights trade-offs.