ZK WHITEBOARD SESSIONS
From May 17th to 19th, we had the pleasure of organizing ZK Hack Kraków, our 3rd in-person ZK-focused hackathon. The event took place in a beautifully renovated building on the east side of Kraków: CKF_13 Centrum Konferencyjne Fabryczna, at the site of the former Polmos vodka distillery. With its blend of Art Deco elegance and industrial style, it impressed the sponsors and the participants (and the organizing team too!) and was an ideal setting for our hackathon focused on cutting-edge technology and innovation.
Day 1: Setting the Stage
Our schedule mirrored the successful format from Istanbul, with an introduction to ZK as a starter. We began with an overview of the ZK landscape, for those less familiar with the industry, to highlight the various categories of companies and technologies. It was also a good moment for us to say a word about the unique approach required for this ZK-focused hackathon, which is more technical than other web2 or even web3 hackathons. In this event, hackers were encouraged to build either ZK applications or ZK core infra.
In the afternoon, our Top Sponsors, Aleph Zero and o1Labs/Mina, conducted workshops to familiarize hackers with their tools and technologies. Following these sessions, we hosted ZK Hack Kraków official kick-off, outlining the weekend’s schedule and all important info, such as bounties and prizes… This edition set a new record with a total amount over $100K! After a tasty dinner, it was finally time for the real hacking to begin.
Day 2: Hacking and Creativity
Saturday was a full day (and night) of hacking, with Office Hours hosted by our Top Sponsors, Aleph Zero and o1Labs/Mina, as well as by our Based Sponsors: Nethermind Research, Gevulot, Hylé, Avail, Polygon, and zkLighter.
The afternoon also featured our now-traditional creative workshop, where hackers took a break to design their own T-shirts and tote bags… sometimes very zk-inspired!
Throughout the day, we interacted with participants, noting the impressive quality of projects shaping up for Sunday submissions. Some notable projects, which would later make Honorable Mentions, included:
• GevuRisc: Andrzej gave a shot at integrating RISC Zero prover/verifier into Gevulot’s decentralized proving layer
• Hackstir: Marton and Shuang worked on a Goland / Gnark implementation of the paper STIR: Reed–Solomon Proximity Testing with Fewer Queries
• Gitcoin Passport: Pawel focused on the portability of a Gitcoin Passport score in a privacy-preserving way
• Who’s Rugging Who?: Miezko and Mork built a revisited version of the game Mafia, also known as Werewolf
• zkPeer: Ushana, Rute and Monika created a prototype for a zk-based DeSci platform enabling anonymous scientific journal publishing and reviewing
• Clarity: Pia, Marcello, Bartosz and Cody developed a tool to look up the source code of a circuit from its identifier (such as the hash of a Cairo program)
• iocz: Kyrre took a stab at FHE and tried to express detection queries on encrypted data using backend-agnostic APIs
• Cluesum: Rob, Sergey and Syed implemented an aggregation scheme for vanilla BLS signatures with silent setup
• n0tte: Francesco and Giacomo tackled the problem of privacy for on-chain inference by using FHE on a one-layer MLP network
Day 3: The Final Push
By Sunday morning, with some participants showing red eyes from a sleepless night of hacking, the air was getting thinner as we were approaching the fateful hour… The project submission deadline was noon, and as the number kept going up in the last minutes, we were eventually thrilled to see 40 projects submitted – an excellent number reflecting the event’s success!
After a brief lunch break, judging began. Our team of 16 all-star judges, split into 4 groups, spent 2.5 hours reviewing the projects and then agreeing on a Top 3, a Chewing Glass award for the best technical project, and a shortlist for participants to vote for the Hackers’ Choice. And here are the winners…
• Chewing Glass Prize went to Air Fried Gyatt: Philippe and Josef created a new backend for the zk-DSL Noir powered by STARKs (Plonky3), thus giving an alternative to Barretenberg but also showcasing the steps how to build a Noir backend
• Hackers Choice Prize went to CornHub: Théo and Michael built a privacy-preserving age verification process using passport scan and zk-proofs to ensure that only adults can access their corn connoisseurs website called CornHub
• 3rd Prize went to chip0: Ayush worked on a PoC implementation of the CHIP-8 instruction set using STARKs – essentially putting together a zkVM by himself in 2 days using Plonky3! – in which he was able to prove a playing of the Snake game
• 2nd Prize went to Private UTXO Discovery: Chee and Kai dived into Private Information Retrieval (PIR) and oblivious transfers to come up with a new data structure and a protocol allowing discovery of UTXO without requiring users to sync the app from scratch
• 1st Prize went to Gemstones Builders: Dawid and Jakub developed a Factorio-like game powered by zk to allow for secret strategies; but they build the ecosystem around it too, since the items produced in-game are effectively ERC20 tokens which can be traded freely
Closing Ceremony
Our sponsors also spent the afternoon judging their respective bounty tracks, engaging with the various projects who were eligible to their own criteria.
By 4:30 PM, we were ready for the closing ceremony. This time, we had the opportunity for winners to present their work to the audience, showcasing the details of their projects and the impressive results of their efforts.
As the hackathon was reaching its conclusion, it was then time for an afterparty exclusively sponsored by Aleph Zero at the Utopia bar next door, featuring the Vodka Factory Museum of the venue! A perfect way to say goodbye after 3 days full of emotions, hardwork and ZK.
We are incredibly grateful to our team, our volunteers, the participants and the sponsors for making ZK Hack Kraków a resounding success. We look forward to seeing you at our next event, ZK Hack Montréal, from August 9th to August 11th.
Thank you & à bientôt in Canada!
