About

I am a research scientist at Mysten Labs working on the Sui blockchain. I am also affiliated with the computer science department of University College London (UCL).

My research interests are in distributed systems, blockchains, and privacy enhancing technologies. These days I mostly work on Byzantine fault tolerant systems for blockchain applications including consensus protocols, consensus-less (broadcast-based) algorithms, and distributed execution engines. I spend most of my time developing new algorithm to produce more performant distributed systems. A key aspect of my work is to leverage all the resources available to the machine and scale blockchain validators to run on multiple machines.

The typical goal of my projects is to go beyond the research stage, I spend considerable effort to implement and evaluate systems to ultimately run them in production. Feel free to drop me an email if you would like to work with me or get in touch.

 Short Bio

I received my PhD from University College London (UCL) advised by George Danezis and Jens Groth. During my PhD I co-founded chainspace.io, which built a scalable and privacy-preserving smart contract platform. Chainspace scales by sharding its state among sub-quorums of nodes and supports privacy-preserving smart contracts by separating the contract’s execution logic from its verification through zero-knowledge proofs. The company was built from several academic works such as Chainspace, Byzcuit, and Coconut (the first three chapters of my PhD thesis). We were then acquired by Facebook (now named Meta) in February 2019.

I then helped design the Novi wallet and Libra payment system. Designing Libra (later renamed Diem) required numerous research innovations such as the Jolteon consensus protocol, the Carousel leader election protocol, and the Twins testing framework. The project also led to the creation of the open-source and production-ready Diem codebase that became the foundation of Aptos.

While at Meta I also co-authored the FastPay consensus-less payment system (the last chapter of my PhD thesis), the Narwhal DAG-based mempool, and the Bullshark consensus protocol. I then left Meta in 2022 to commercialize these projects, branded as Sui.

 Selected Publications

Sui Lutris: A Blockchain Combining Broadcast and Consensus

Same Blackshear, Andrey Chursin, George Danezis, Anastasios Kichidis, Lefteris Kokoris-Kogias, Xun Li, Mark Logan, Ashok Menon, Todd Nowacki, Alberto Sonnino, Brandon Williams, Lu Zhang
Conference on Computer and Communications Security (CCS), 2024
✨ Commercialized by Sui

Bullshark: DAG BFT Protocols Made Practical

Alexander Spiegelman, Neil Giridharan, Alberto Sonnino, Lefteris Kokoris-Kogias
Conference on Computer and Communications Security (CCS), 2022
✨ Commercialized by Sui
✨ Adopted by Aleo
✨ Adopted by Fleek

Narwhal and Tusk: A DAG-based Mempool and Efficient BFT Consensus

George Danezis, Lefteris Kokoris-Kogias, Alberto Sonnino, Alexander Spiegelman
European Conference on Computer Systems (EuroSys), 2022
✨ Best paper award
✨ Commercialized by Sui
✨ Adopted by Fleek
✨ Adopted by Aleo