# Introduction

Learn.0xparc.org was born out of the First Applied ZK Learning Group by 0xPARC in December 2021. Since then, we have updated lecture materials to be from the Second Applied ZK Learning Group (March 2022), but have kept old videos for reference. These Applied ZK Learning Groups are the introductory track for understanding ZK concepts, using the Circom toolstack to build applications. In June 2022, we ran the Halo2 Learning Group to further build on that knowledge using the PLONK proving system.

This is an evolving collection aimed to collate the best resources for someone diving into the applied ZK space. One particular area of focus is to add materials for bringing those without a formal mathematics background up to speed. ZK theory is inherently math-heavy and the current cohorts assume a strong background in algebra, number theory, and cryptography. However, over time, we hope to develop materials for motivated engineers with solid CS backgrounds but limited knowledge of advanced mathematics.

Lastly, we have some ideas on interactive ZK learning. With the development of zkrepl.dev, we hope to add some interactive exercises and possibly extend those as the tooling progresses.

## About ZK Learning Group Lectures

We have also included key takeaways and high-level questions to accompany some of the more math-heavy lectures, along with some supplemental readings. It’s difficult to absorb 100% of the material on the first run through, so we’ve identified the essential concepts to take away from each lecture.

Further, we hope the takeaways and questions help you get a feel for how these topics fit together in the bigger picture. In fact, it might even be helpful to review these sections ahead of watching the lecture!