The Fair Drop Raffle Has Ended!

0x060d...58e9 You win an NFT art piece by Zach Lieberman!

Our Demo:

This raffle is a demo of using the technology developed by researchers from Cornell, CANDID and Town Crier in particular, to establish privacy-preserving unique identities on blockchain and prevent scalping bots in NFT drops.

The problem:

Today, profit-seekers are able to use bots to buy up large amounts of NFTs at drops and then resell them at higher prices—much as scalpers do in conventional markets, e.g., the Time Magazine's NFT launch. This practice is disruptive to the NFT market, as it creates a sense of unfairness. Among other things, it has raised concerns with artists who wish their NFTs to go to collectors interested in their art, rather than bot creators.

Our solution:

We utilized the decentralized identity system called CanDID to help enforce a one-NFT-per-person drop policy by establishing privacy-preserving unique identities based on data from trustworthy websites such as the Social Security Administration (SSA). Many other user characteristics can be proven using CanDID, e.g., eligibility conditions such as adult-only-NFT (or) country-only-NFT.

For this demo, we built a tool based on Town Crier to scrape name from the SSA or Coinbase website, or alternatively the ownership list of Proof of Attendance Protocol, and use the information to deduplicate identities inside Intel SGX, a trusted execution environment, to guarantee integrity and protect users' privacy. Check out our video demo.

We won bounties from the generous Chainlink and Pocket Network sponsors at ETH Denver 2022!


Yan Ji

PhD Student

Yan Ji is a PhD student at Cornell University.

Tyler Kell

Research Engineer

Tyler Kell is a research engineer at IC3. In a previous life, Tyler was a penetration tester, and enjoys an extensive history of breaking security assumptions.

Deepak Maram

PhD Student

Deepak Maram is a final-year PhD student at Cornell Tech whose research interests lie in applied cryptography. Common themes include enriching blockchains with new functionality and building user-centric systems.

Kushal Babel

PhD Student

Kushal is a third year PhD student at Cornell University.

Advised By

Ari Juels


Ari Juels is the Weill Family Foundation and Joan and Sanford I. Weill Professor in the Jacobs Technion-Cornell Institute at Cornell Tech and the Technion and a Computer Science faculty member at Cornell University. He is a Co-Director of the Initiative for CryptoCurrencies and Contracts (IC3). He is also Chief Scientist at Chainlink.