ZK Noir ecrecover

This is a simple Noir demo that shows how to use dependencies in a Noir project.

This circuit verifies a signature without revealing the signing address.

Usage

1. Clone this repo

git clone https://github.com/Cyfrin/zk-ecrecover-cu.git

2. Navigate inside the circuits folder

cd circuits

3. Create the Prover.toml file

nargo check

Then fill in the inputs in the Prover.toml file.

Generating the inputs

Generate the message

cast keccak "hello"

Sign the message

cast wallet sign --no-hash --accpunt <name-of-your-keystore> <bytes-output>

Get your public key

cast wallet public-key --account <name-of-your-keystore>

The first 32 bytes are the x value and the second 32 bytes are the y value.

Paste into inputs.txt as bytes

Add the values in the file:

expectedAddress = "0x52d64ED1fd0877797e2030fc914259e052F2bD67"
hashed_message = "0x1c8aff950685c2ed4bc3174f3472287b56d9517b9c948127319a09a7a36deac8"
pub_key_x = "533367042c3e9456fec155940165c28c01fe6e28601337df50562ddc4f36bfb9"
pub_key_y = "7dcafe27cadbe10861bb67e0599382f79dc29c1d39d93b10f716c8ceff1743ed"
signature = "0xdd935f778351217ec02e6f857e47f0cea837380f30eccf63742b9a97cf1872b4316700b028504591f6b31203b86ccb3363353eedd8f9cf4f344a769c689525b31b"

Populate the Prover.toml

chmod +x generate_inputs.sh
./generate_inputs.sh

4. (optional) Compile the circuit

Do this step if you want to create a verifier smart contract without creating a proof (if you want users to create witnesses and proofs later).

nargo compile

5. Execute the circuit and generate a witness

This step will also compile the circuit.

nargo execute

6. Create the proof

bb prove -b ./target/circuits.json -w ./target/circuits.gz -o ./target

bb prove --oracle_hash keccak -b ./target/circuits.json -w ./target/circuits.gz -o ./target

7. Create the verification key

7.(a) For off-chain verification

bb write_vk -b ./target/circuits.json -o ./target

7.(b) For an on-chain verifier contract

bb write_vk --oracle_hash keccak -b ./target/circuits.json -o ./target

8. Verification

8.(a) Off-chain verification

bb verify -k ./target/vk -p ./target/proof

8.(b) Generate an on-chain verifier contract

bb write_solidity_verifier -k ./target/vk -o ./target/Verifier.sol