Preparation

pnpm install && pnpm prepare
git submodule update --init --recursive

forge build

Contract relationship

Deploy Contract

• Make sure .env (for mumbai) .prodenv (for mainnet) is set properly

build

forge build --build-info --build-info-path buildinfo.txt --use solc:0.8.13

For mumbai test net(80001)

$ source .env
$ forge script script/FakeNFT.s.sol:FakeNFTScript --rpc-url $RPC_URL --private-key $PRIVATE_KEY --broadcast -vvvv

Contract	Address
FakeNFT	0x51a1B628d9a2CFb76306FDccb39E56382A64482B
TalentVerifier	0xb52b844F9c9481Bcb8CdDb44e6E8322267627fb6
VerifyForwarder	0x8bb9c7c130aec8947a72ae5cd0d361b285a7b8c1
NoxxABT	0xc8984bcf50fe9a864b5184bb83cfd968805067b7
Noxx	0x264b66f5113892AAEA263df76A140dF67c0f7554

For main net(137)

$ source .prodenv
$ forge script --rpc-url $M_RPC_URL --verify --use solc:0.8.13 --private-key $M_PRIVATE_KEY --chain-id 137 --broadcast -vvvv --etherscan-api-key $M_SCAN_API_KEY script/Forwarder.s.sol:ForwarderScript

Contract	Address
FakeNFT	-- NA --
TalentVerifier	0x230A32770B8a339871D5EF1C63675BEc9e5D3404
VerifyForwarder	0x97b9333204bc6E53F9a1ff7794F01A10Cf1cdF52
NoxxABT	0x0e5560636b320E07f6F88297276c8B60D7B31cFf
Noxx	0x15008034Ae7CB379f35A0C9CEfDA7b4C612c191c

Verify

For mumbai test net(80001)

$ forge verify-contract {GUID} {Contract} --chain 80001 --verifier sourcify
$ forge verify-check --chain 80001 --verifier sourcify --etherscan-api-key $SCAN_API_KEY {GUID}

For mainnet(137)

$ forge verify-contract {GUID} {Contract} --chain 137 --verifier sourcify
$ forge verify-check --chain 137 {GUID} --etherscan-key $M_SCAN_API_KEY

Zero-knowledge proof

What is ZK proof

• A proof such that
  • A legal name from KYC matches given user inputs
  • Age is over 18
  • A residential country is not restricted to work with a company in the US(Noxx)

Workflow

Circuits

Circuit is written in Noir:here

• Private inputs
  • name
  • residential country(from tax document)
  • age(based on their DOB)
  • nonce(Generated in the local PC to ensure the values have not been tampered)
• Public inputs
  • commitments that are paired with private inputs. Generated with poseidonHash(val, nonce)
  • age: 18, we expect this user is above 18
• Verification
  • Checks poseidonHash(value, nonce) == commitment for each field
  • Checks range proof for age
  • Checks country is in the Merkle tree of allowed countries (see MerkleTree)

Development

Install Noir to your system. See https://noir-lang.org/ for the instruction. 0.7.1+ is required.

1. Generate Verifier.sol

$ nargo codegen-verifier

Place it under src/

cp plonk_vk.sol src/TalentVerifierV2.sol

2. Generate proof

Prepare Prover.toml

$ nargo prove

This will generate proofs/main.proof

3. Verify the proof

$ nargo verify

Appendix. Generate proof for Solidity

Generates Solidity inputs. Result will be in input.txt

$ pnpm ts-node --esm node-script/verifyProof.ts

Updating submodule

The command below updates all submodules

git submodule update --recursive --remote --merge

MerkleTree for CountryCode

See MerkleTree