Before Blockchains, There Was State Machine Replication

DARPA had recognized that this was a serious problem, the problem of malicious attacks, and was looking for research in that area. I had a student, Miguel Castro. He came to me and he said, why don't we see whether we can figure out a way to do replication that handles these malicious attacks? And that seemed like a great idea. The problem, if the primary failed, the primary that was running the protocol, the whole thing came to a crashing halt. We came up with a protocol that if the primary seemed to not be doing its job, the backups then carried out another protocol in which a different replica became the primary. We thought that at some point, people would start to use this, and then along came blockchains. And so that was very funny. Someone who loves computer science, loves research, wants to do important work, wants to have an impact, What would you suggest as kind of a mindset, as an approach? Computer science is in a very strange place right now with the advent of AI. I think that as far as research is concerned As part of our summer feed drop series, we're sharing another episode from the a 16 z crypto show. Every blockchain today relies on replication techniques first developed in the nineteen eighties, years before anyone imagined cryptocurrencies. In this episode, Tim Roughgarden and Atai Abraham speak with Turing Award winner, Barbara Liskov, whose pioneering work on distributed systems, state machine replication, and practical Byzantine fault tolerance laid the foundation for many of today's blockchain protocols. Whether you're new to crypto or already building in the space, this conversation offers a deeper understanding of the computer science behind modern blockchains. If you enjoy this episode, be sure to follow the a sixteen z crypto show for more conversations like this. Hi, everyone, and welcome to First Principles, a series by the team at a sixteen z Crypto. I'm Tim Roughgarden. I'm the head of research at a sixteen z Crypto. And today, we're exploring a core challenge in distributed computing. How can a system remain reliable when some of its parts fail or behave maliciously? In this episode, we're going to speak with the Turing award winning computer scientists whose work helped answer this question, Doctor. Barbara Liskoff. She's famous for many things, but today we're gonna focus on her work that laid the foundations for modern Blockchain systems. For example, from view standard application from the nineteen eighties, to Practical Byzantine Fault Tolerance or PBFT a decade later. A16z crypto research partner, Ittai Abraham, joins me as we talk with Doctor. Liskov about her path from programming languages to distributed systems, the evolution of practical replication protocols, the state machine replication paradigm underlying blockchains, and how emerging technologies like AI are reshaping systems research. Here's our conversation. Professor Liskopf, thanks so much for joining us for the conversation today. I really appreciate you taking the time. Sure. I thought maybe …