ZK WHITEBOARD SESSIONS
From August 9th to the 11th, we hosted our 4th in-person ZK-focused hackathon in beautiful Montréal, Canada.
The event was truly one like no other! On one side, we for the first time connected with the North American (and especially the Canadian) ZK community! We had an amazing group of hackers join us in building the next generation of ZK applications and implementations. Our partner RISC Zero hosted a weeklong hacker house around our event further connecting the members of the community as well.
On the other hand, the event had a couple hiccups! Like the hurricane that hit Montréal on our first day, knocking the power out just after we kicked off the event. The power never came back on, so we needed to switch locations on Saturday morning. Luckily after the switch, the event continued on without a hitch and we rounded out the weekend inspired and excited about the state of the ZK ecosystem and the amazing ideas that the hackers shared with us!
Day 1: Setting the Stage
On Friday, right after lunch, we opened the doors to the amazing venue that was the Rialto Theater, a designated National Historic Site of Canada built in the 1920s on Park Avenue in the vibrant Mile End neighborhood of Montréal.
Intro
In an ongoing effort to share, educate and promote the world of Zero Knowledge, this edition’s opening day was for the first time open to the public, bringing more people from the local dev community and beyond to meet with the ZK community.
We began with a presentation from the ZK Hack team introducing ZK, showing how the ecosystem has grown over time and explaining the languages and tools for hackers to use during the weekend.
Workshops
In the afternoon, our Top Sponsors RISC Zero and Polygon, conducted workshops to familiarize hackers with their tools and technologies.
Kickoff
Time had come for the official ZK Hack Montréal Kickoff, where the ZK Hack team outlined the weekend’s schedule and all important information (prizes!), and where sponsors took the stage to introduce their bounties and what they were hoping to see built or implemented by the participants.
All the recordings of ZK Hack Montréal presentations are available on ZK Hack’s playlist on Zero Knowledge Youtube channel.
Evening
While inside, we had spent the day learning and brainstorming ZK ideas, outside, Montréal was being hit by the post-tropical storm Debby. The downpour flooded homes and roads across the province, while knocking out power for more than 500,000 homes at the peak of outages. The greater Montreal area received an accumulation of 150 millimeters in 24 hours, far exceeding the average rainfall for the entire month of August – 94 millimeters – (Environment and Climate Change Canada).
The Theater was not spared and we lost power right around dinner time, turning our meal break into one of these “Dining in the Dark” experiences – a new way for everyone to discover the local poutine!
This did not deter the hacker’s mood much, and many jumped straight in and started hacking in the dark until we closed!
Day 2: Re-setting the Stage
Day 2 started with the news that the Rialto theater was still without power. But luckily we found another space available for us to relocate our entire hackathon and all our hackers 4.5 kilometers from the Rialto Theater to the St James Theater downtown – no small feat! This new venue, the former headquarters of the Canadian Imperial Bank of Commerce (!), with 70 feet high stone walls, marble & wood floors and a suspended stained-glass dome, complete with the original safes in place, made it a memorable hacker room!
All of Saturday (and early Sunday morning) was time for hacking, with Office Hours throughout the day for participants to meet the engineering teams from our Top Sponsors RISC Zero and Polygon, as well as Based Sponsors Gevulot, Novanet and o1Labs.
Throughout the day, we interacted with participants, noting the impressive quality and variety of projects shaping up for Sunday submissions. Here are some notable projects that would later contend for the top prizes:
– zk blackjack: Andrew worked on a decentralized rollup solution for better on-chain blackjack experience (by introducing a user’s ephemeral keys that can be used only for a current game, and becomes invalid afterwards).
– ZKompose: Kai, Arvini and Arian created a proof-of-concept dApp (on-chain Fantasy football) that allows IPFS content to be composed into new derivatives that are produced in a verifiably correct context.
– Provable Multiparty Delay Encryption: John and Owen tried multiple different proving systems with unique approaches to efficiently implement an exponent range proof check. A definite Chewing Glass contender!
And also:
– zgate: Thomas worked on gated access to Telegram group chats using ZK proofs, removing the need for a trusted party.
– NTBNTS: Eli worked on generating proof of winning in a NTBNTS (not too big not too small) game.
– zkAds: Valentin and Antoine built a platform that uses ZK proofs to protect user data while enabling advertisers to target relevant users.
Hacking continued well into the night …
Day 3: Last Push
Day 3 of the hackathon started filled with determination as participants who had stayed overnight, along with those who managed to get a bit of rest, gathered back at the venue for a final push. Fueled by a healthy vegan and gluten-free breakfast courtesy of lu & i bakery, everyone was ready to continue hacking until project delivery at noon. The atmosphere was charged with energy as 25 projects were completed, showcasing the dedication and creativity of all the teams.
After a brief lunch break, judging began. Our team of 15 all-star judges, split into 4 groups, spent the next few hours reviewing the projects and then agreeing after much debate on a Top 3, a Chewing Glass award for the best technical project, and a shortlist for participants to vote for the Hackers’ Choice.
The sponsors also spent the afternoon judging their respective bounty tracks, engaging with the various projects who were eligible to their own criteria.
Closing Ceremony
By 16:00, everyone was ready for the closing ceremony. We had the Top and Based Sponsors join us on stage to give out their prizes before we announced our Chewing Glass, Hackers’ Choice and Top 3 winners of ZK Hack Montréal. About 50K$ in prizes were awarded to the hackers that day!
The winners had the opportunity to present their work to the audience, showcasing the details of their projects and the impressive results of their efforts.
ZK Hack Montréal Winners
And here are the winners…
– The Hackers’ Choice Prize went to Pictionary Proof: Jaskirat and LN developed a multiplayer drawing game with a provably fair and privacy-respecting scoring mechanism using zero-knowledge machine learning (zkML). The game involves players drawing based on a secret category, with their submissions scored by a neural network and verified through a zkVM
– Two teams tied for the Chewing Glass Prize:
– sparta(0): Simon and John implemented SuperSpartan, a Polynomial Interactive Oracle Proof (IOP) for the Customized Constraint System (CCS), written in Rust. SuperSpartan leverages the sum-check algorithm to efficiently prove that a CCS relation holds, offering flexibility (R1CS, Plonkish, AIR), and serving as a foundational component for more complex recursive proof systems; and
– Plonky3Sum: Syed implemented a proof system for the correct aggregation of public keys using twisted Edwards coordinates in Plonky3. This method reduces verification costs by directly using public keys on twisted Edwards curves, such as the Bandersnatch curve, without conversion. The project has critical applications in blockchain consensus proofs for resource-restricted actors, anonymous verifiable voting, and anonymous leader election.
– 3rd Prize went to Zalileo: Théo, Koen, Rémi & Yofi addressed the issue of GPS spoofing, which undermines the reliability of existing Proof of Location protocols. By leveraging Galileo’s OS-NMA technology, which signs navigational messages using ECDSA, they were able to ensure the authenticity of location data, reducing the risk of GPS manipulation.
– 2nd Prize went to DrinKZ: Harry & Non-Econ aimed to establish trust in real-life IoT data, starting with scenarios like DUI accusations, by enabling verifiable and privacy-respecting data ownership. By integrating Apple’s App Attest service with zkVM, the project ensures that data collected from analog sensors on IoT devices, such as breathalyzers connected to an iOS app, is both authentic and securely attributed to the device owner, addressing the oracle problem for real-world sensing data.
– and the ZK Hack Montréal 1st Prize went to Lemma: Jakub, Kit & Eric built a project that innovatively applies ZK technology to mathematics by creating a decentralized platform where users can post unsolved theorems with accompanying bounties. Valid mathematical proofs are verified on-chain using ZK proofs, enabling trustless bounty distribution, which could accelerate mathematical discoveries by bridging advanced mathematics and blockchain.
Congratulations to the winners of this edition, and to all the participants!
Lessons Learned / What’s Next
The projects that came out of this edition showcased the versatility and potential of ZK proofs in enhancing privacy in various applications, as well as solving real-world problems, exploring insanely creative new use cases like ZK breathalyzers, ZK & GPS and many more!
And just like that, ZK Hack Montréal came to an end. It was an incredible experience made possible by the amazing ZK Hack team. We had never expected a mid-event venue switch, and all the challenges that the venue and weather threw at us, but the team managed it with speed, professionalism and with good humor throughout. It definitely made for a truly unforgettable event!
A big shoutout to our fantastic partners – Top Sponsors RISC Zero and Polygon, as well as our Based Sponsors Gevulot, Novanet and o1Labs. We’re also grateful to our Prize Sponsor ZKV, our Community Sponsors Pluto, Aligned, zkVerify, Fenbushi Capital, Lambda Class, 1kx, Aztec and Celestia, to our judges, that did an incredible job reviewing all the fantastic projects submitted by the participants, to our Platform partner Devfolio for supporting the hackers all week-end, and to the crew at the venue.
Lastly, a big big thank you to all the participants, we can’t wait to see you at the next one!
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