NERD: Nifty Erdstall. An off-chain NFT marketplace with confidential NFTs. Scaled with Erdstall.
NERD aims to be a reusable NFT marketplace framework that uses the Erdstall scaling technology in the background. Erdstall was introduced at the ETHGlobal hackathon 2020 by the same team. A unique feature of NERD are cNFTs - confidential NFTs. A cNFT grants its holder access to some confidential asset, e.g. a hidden encryption key. The owner can then query the system for, e.g., decryption requests and receives the decrypted data - but only as long as they are the current owner of the cNFT. cNFTs can be used in many applications, e.g., tradable licenses or access to a decryption oracle, decoupling the NFT holder from the secret data. Users can mint, transfer and trade cNFTs off-chain while having their assets inside the Erdstall network. The cNFTs can also be withdrawn from Erdstall, back to mainnet, and reused in other 2nd-layer scaling solutions, since they are just ERC721 tokens. The submitted demo doesn't contain all the mentioned features. We couldn't get it all working in time. Therefore, the demo highlights the cNFT minting procedure.
How it's made
The frontend demo is made with React in TypeScript. It connects to the Erdstall operator via websockets and queries the NFT assets server via http. Assets of cNFTs are server encrypted in a way that only the NFT holder can decrypt them. This is just a simple example application of how cNFTs could be used. The Erdstall system is build in Go, but is not part of the submission. The NFT Server is part of the submission and is also written in Go.