ricy137 / ghotip-zk

Tipping annonymously with zero-knowledge proof and GHO

GHOTip

For quick and comprehensive understanding : please review our project page in ETHGlobal

Links
live website link	https://reliable-figolla-c2b336.netlify.app/
0.1 GHO contract	https://sepolia.etherscan.io/address/0x820ce4e674ddc611ee2827f21faa6c9df6bb490b
0.5 GHO contract	https://sepolia.etherscan.io/address/0x196f362Ebc50A4e166BD8cBB88De3BE3d1851d76

How it's made

GHOTip leverages Zero-Knowledge Proofs (ZKP) for secure and anonymous transactions. It utilizes a smart contract system where users deposit tips in $GHO stablecoin into server's vault contract(GhoTip contract) anonymously. Drawing inspiration from Tornado Cash, this approach introduces enhanced anonymity and security. Every vault contract(GHOTip contract) would only accept fixed amount of $GHO in each deposit, and currently we provide 0.1GHO and 0.5GHO, two kinds pool. By using fixed tip amounts, GHOTip further safeguards user anonymity, making the tipping process uniform and discreet. And users can safely verify their payment of Tips with proof, which won't reveal users' identity during depositing.

Techs used and where they're located

Detailed explaining files for local setup is in README.md under each folders

zk (under circuit folder; circom, snarkjs)

They're originally written in circom and using snarkjs for G16 setup. The main circom files are deposit.circom and withdraw.circom deposit_js and withdraw_js folders are automatically generated during the compiling of circom files (deposit.circom and withdraw.circom ). And files under the two folders plus setup_final.zkey file are used in frontend for proof generation. The Verifier.sol is automatically generated by snarkjs and is used as a helper contract in GHOTip.

contracts (under contracts folder)

Managed by hardhat, the main contract is GhoTip.sol, and the rest solidity files are helpers/utils.

contract name	description
GhoTip.sol	main contract for all interactions
MiMSonge.sol	helper contract for hashing
ReentrancyGuard.sol	OpenZeppelin contract
IGhoToken.sol	GhoToken interface
Verifier.sol	helper contract for verification, generated by snarkjs

deploy.js is under scripts folder to help you deploy the contracts.

frontend

framwork	Nextjs
zk helper	snarkjs and files mentioned in above zk
coonecting wallet	ConnectKit
interaction with blockchain	wagmi