Theory to code: Building the breakthrough zkVM Jolt

Justin ThalerSam RagsdaleMichael ZhuRobert Hackett

Verifiable computing is a method for trustlessly outsourcing computation — and it’s a fast-developing area of technology that could help scale blockchains and, more broadly, decentralize the internet. We explore this world through the lens of zkVMs — or zero-knowledge virtual machines — tools that enable computers to prove that they ran programs correctly, as well as the SNARKs that enable them to work their magic. In this episode, members of the a16z crypto research and engineering teams discuss their year-long close collaboration to develop the simplest, most performant zkVM to date: Jolt.

Welcome to web3 with a16z, a show about building the next era of the internet by the team at a16z crypto. That includes me, host Robert Hackett.  Today’s all new episode covers a very important and now fast developing area of technology that can help scale blockchains, but that also has many uses beyond blockchains as well.

That category of technology is verifiable computing, and specifically, SNARKs.  So today we dig into zkVMs, or “zero knowledge virtual machines,” which use SNARKs, and we discuss a new design for them that the guests on this episode helped develop — work that resulted in Jolt, the most performant, easy-for-developers-to-use zkVM to date.

The conversation that follows covers the history and evolution of the field, the surprising similarities between SNARK design and computer chip architecture,  the tensions between general purpose versus application specific programming, and the challenges of turning abstract research theory into concrete engineering practice.

Our guests include Justin Thaler, research partner at a16z crypto and associate professor of computer science at Georgetown University, who came up with the insights underpinning Jolt, along with collaborators from Microsoft Research, Carnegie Mellon, and New York Universities.  His is the first voice you’ll hear after mine,  followed by Sam Ragsdale, investment engineer at a16z crypto, and Michael Zhu, research engineer at a16Z crypto, both of whom brought Jolt from concept  to code.


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