Here’s Who Built on Quorum at ETH Denver

A smooth web3 experience with permissioned features, a security token platform with privacy features, and a supply chain use-case on Quorum.

ETHDenver — oh, the land of Bufficorns and Ethereum developers!

The Quorum team was lucky enough to make it out to Denver, Colorado to meet with all kinds of interesting people BUIDLing for web3 and beyond. The amount of projects buidl-ing on top of Ethereum, MakerDAO, POA, Zeppelin — to name a few — were just mind blowing.

I’ll tell ya, if you’ve been to one of these Ethereum ecosystem events, you know the feeling. The thrill of being around the Ethereum community and truly experiencing a future with distributed technologies first hand — and without just discussing it all day — can make your brain numb. I could go on all day about how amazing the event was, but I’ll let you read about it, here.

That being said — we were excited to work with teams that wanted “buidl” on Quorum.

We offered three (3) bounties to give developers a little incentive. We were looking for projects that had the best use of Quorum’s privacy features, best use of Quorum’s performance/ transaction speed, and the best use of any public Ethereum tools with Quorum.

And we received some pretty awesome submissions!

1. Tidbits

Team Members: Bradley Clarke, Gabe Ibarra, Taylor Dawson

Tidbits Architecture via Bradley Clarke

Tidbits is web3 with no extensions, no modals, just flow. That being said, you can offload the tricky stuff to the network. This is a simple game with a simple experience where you assemble brief poems like word magnets. Visitors to the site who arrive without an in browser wallet are given a key. A unique contract then manages gas for the user, ensuring that there is always just enough (test) ETH in their wallet to keep playing. Tidbits is a great use-case for Quorum, and ended up making it to Top 20 on the main stage!

Here’s their full tech stack:

  • Dapp runs on Quorum POA network
  • Custom Oracle using ION protocol bridges Rinkeby to POA network
  • Decentral Key / Transaction manager accepts login from OAuth provider (Google) to create keys for user. Also signs transactions.
  • Dapp incorporates a gas management contract
  • Rinkeby based subscription manager to allow Dapp developers to keep their dapp running


2. RToken

Team Members: Shane Jarvie, Elena De La Paz, Ryan Hall

RToken Architecture via Shane Jarvie

RToken is a token issuance and trading platform combining the open source R-Token compliance standard for digital securities with the institutional grade privacy features of the Quorum blockchain. This security token platform leverages the R-Token protocol and Quorum for global regulation while preserving issuer and transaction privacy. Yeah, it’s a mouthful — but it’s pretty awesome nonetheless.

For the compliance aspect, they implemented the industry standard ERC-20 method of transfer() and transferFrom() with an additional check to determine whether or not a transfer should be allowed to proceed. The implementation of check() can take many forms, but a default whitelist approach is implemented by TokenRegulatorService. Token and participant-level permissions, when used in different combinations, can be used to satisfy multiple regulatory exemptions. The ServiceRegistry is included as a mechanism to facilitate upgrading the R-Token check logic as rules change over time. This R-Token then leverages the Quorum privacy platform by allowing issuers to share knowledge of state while remaining agnostic to each other’s trades.

This allows for issuers to only view their own token balances and state, while querying a global regulator service when attempting to make a transaction, and for no public entity outside of the regulator to be able to view all issuer transactions.

The RToken team also built a stunning user interface which you should definitely try out!

Here’s their full tech stack:

  • Quorum
  • Solidity
  • React
  • Docker


3. GeoHunter

Team Members: Bryce Doganer, Andy Watt, Gareth Oates, Colin McCrae, Lucas Henning

GeoHunter is a tracking DApp in treasure hunt format that consists of a series of QR codes which must be scanned by users in the correct order. Each QR code has an associated picture stored on IPFS which shows its location, with the IPFS hash (and all user and tag data) stored on the blockchain. The fastest user to scan all the QR codes in the correct order wins. A leaderboard can be viewed showing the fastest times, and the status of players currently on the treasure hunt. The DApp is hosted on a Quorum node on AWS. What’s cool is that this project is the basis for a supply chain item tracking DApp which is in line with UN Sustainable Development Goal 8: Decent Work and Economic Growth. What seems like a simple use-case could have huge impact in global supply chain transparency amongst permissioned parties.

Here’s their full tech stack:

  • Truffle v5.0.4 (core: 5.0.4)
  • Solidity v0.5.0 (solc-js)
  • Javascript
  • Ganache CLI v6.3.0 (ganache-core: 2.4.0)
  • IPFS (go-ipfs version: 0.4.18)
  • Quorum (an enterprise version of Go Ethereum that addresses transaction privacy trough a permissioned group of known participants, high speed, network-wide transparency, and high throughput)
  • OpenZeppelin-solidity
  • React
  • uPort
  • QR Codes


In all, we were able to work with some incredible projects with real world use-cases. Although these were our bounty recipients that were oh, so proud of — there are additionally a handful of hard working developers that spun up Quorum nodes this past weekend — and we appreciate you.

If you’re looking for more info on Quorum, or want to get in touch with these teams — join our Slack channel, or Sign In!

Thanks for BUIDLing with us!

Matt Wright

Community Manager, Quorum