AMM DEX with ZK

A decentralised exchange similar to uniswap, with option to swap with zero-knowledge

What is zero-knowledge-ed?

Assuming you're familiar with zk already, we used Zokrates to let traders swap in ETH and withdraw tokens later. All the calculation is still performed as if the tokens have left the DEX. Such tokens will enters a "waiting room". Only someone who has the zk-snark proof that locks the token will be able to withdraw this asset.

Implementation

Traders who want to use zk features can use our tools, provided here

Using run.sh script, user can generate a sha256 digest from 4 128-bit numbers and a proof, used to prove the knowledge of the pre-image of the digest. User use the digest to send fund, and can use the proof of pre-image knowledge to withdraw.

Call zkSwapETHForTokens function and provide an sha256 digest, which will be mapped to the amount of tokens equivalent to the ETH being sent. The tool will generates a proof.json file, which, when used as parameter for zkWithdraw along with the sha256, will approve and sends the caller the tokens.

Development

Install node packages

npm i

[!WARNING] BEFORE DEPLOY: Update token and exchange address in exchange smart contract

Set these variable in your .env file:

• PRIVATE_KEY="" #private key of deployer
• TOKEN_ADDRESS="" #automatically set when run deploy script
• EXCHANGE_ADDRESS="" #automatically set when run deploy script
• TOKEN_ABI_PATH="./artifacts/contracts/token.sol/Token.json"
• EXCHANGE_ABI_PATH="./artifacts/contracts/exchange.sol/exchange.json"

Run hardhat

  npx hardhat node

• open new terminal, run the following command to deploy

  npx hardhat run --network localhost scripts/deploy_token.js
  npx hardhat run --network localhost scripts/deploy_exchange.js

Referer

• Instruction
• Lecture
• Uniswap v3