Ether EOA-auth SDK (EOA TX Buider)

Technical Stack:

• The Ether EOA-auth SDK (EOA TX Buider) would be implemented with the following technical stack:
  • ZK circuit: written in Circom and Snarkjs .
  • Smart contract: written in Solidity.

Overview

Overview

• The Ether EOA-auth SDK (EOA TX Buider) would be used for account recovery as a secondary account recovery module in the ZK Email Recovery. (NOTE：At the moment, the Ether Email-auth SDK (Email TX Builder) has been used as a primary account recovery module for the ZK Email Recovery. Basically, the Ether EOA-auth SDK (EOA TX Buider) would be assumed that it work with the Ether Email-auth SDK (Email TX Builder) in the ZK Email Recovery)

• The EOA TX Builder would be the module:

  • which can generate a proof to prove that a given account address is associated with a guardian address. (NOTE：This proof is called a EOA proof in this repo)
  • which can generate the Verifier contract that can verify the EOA proof.

• The advantage of using an EOA proof is that a given guardian address, which is associated with an account owner, can be verified without revealing the guardian address.

Integration with the Email-Recovery module

• The Ether EOA-auth SDK (EOA TX Buider) would be assumed that it work with the Ether Email-auth SDK (Email TX Builder) in the ZK Email Recovery

  • Integration summary and approach: https://github.com/masaun/email-recovery/blob/masaun_%2366_prototype-new-ERC7579-recovery-module/doc/summary-and-approach.md

  • The architecture of the proof generation with the Email-auth (which generate and verify a Email proof)and EOA-auth (which generate and verify a EOA proof) (Source: https://github.com/masaun/eoa-tx-builder/blob/develop/doc/diagrams/architecture_proof-generation_with_Email-Auth_and_EOA-auth.png )

  • The architecture of the account recovery flow including both the Email-auth (which generate and verify a Email proof)and EOA-auth (which generate and verify a EOA proof) (Source: https://github.com/masaun/eoa-tx-builder/blob/develop/doc/diagrams/architecture_of_account-recovery-flow_including_EOA-auth.png )

Installation

Installation

ZK circuit (written in Circom and Snarkjs)

• 0/ Install node modules in the root directory

yarn install

• 1/ Move to the ./circuits directory and install node modules

cd circuits && yarn install

• 2/ Compiling ZK circuit

circom multiplier2.circom --r1cs --wasm --sym --c

• 3/ Move to the ./circuits/eoa_auth_js directory

cd eoa_auth_js

• 4/ Computing the witness with WebAssembly

node generate_witness.js eoa_auth.wasm input.json witness.wtns

• 5-1/ Start a new "powers of tau" ceremony

snarkjs powersoftau new bn128 12 pot12_0000.ptau -v

• 5-2/ Contribute to the ceremony

snarkjs powersoftau contribute pot12_0000.ptau pot12_0001.ptau --name="First contribution" -v

• 6-1/ Start the generation of this phase 2:

snarkjs powersoftau prepare phase2 pot12_0001.ptau pot12_final.ptau -v

• 6-2/ Generate a .zkey file that will contain the proving and verification keys (in phase 2)

snarkjs groth16 setup eoa_auth.r1cs pot12_final.ptau eoa_auth_0000.zkey

• 6-3/ Contribute to the phase 2 of the ceremony

snarkjs zkey contribute multiplier2_0000.zkey eoa_auth_0001.zkey --name="1st Contributor Name" -v

• 6-4/ Export the verification key:

snarkjs zkey export verificationkey eoa_auth_0001.zkey verification_key.json

• 7/ Generate a zk-Proof (Groth16 Proof)
  • outputs 2 files are also generated at this point:
    • proof.json: it contains the proof.
    • public.json: it contains the values of the public inputs and outputs.

snarkjs groth16 prove eoa_auth_0001.zkey witness.wtns proof.json public.json

• 8/ Verifying a Proof
  • 3 files (verification_key.json and proof.json and public.json) would be used to check - if the proof is valid.
  • If the proof is valid, the command outputs an OK in terminal.

snarkjs groth16 verify verification_key.json public.json proof.json

• 9/ Generate a Solidity Verifier contract

snarkjs zkey export solidityverifier eoa_auth_0001.zkey verifier.sol

Run the test of ZK circuit (using circom_tester)

• Run test (using circom_tester)

/// NOTE: The directory is ./circuits
cd circuits

yarn test

Smart contract (written in Solidity)

• 1/ Move to the ./contracts directory

cd contracts

• 2/ Compile SC (Main file: EoaAuth.sol)

forge build

Run the test of Smart contract

• 3/ Run Test (File: EoaAuth.t.sol)

/// [NOTE]：Make sure the directory is ./contracts
cd contracts

forge test -vvv

References

• Document of Circom and Snarkjs：https://docs.circom.io/getting-started/writing-circuits/
• Email Recovery module：https://github.com/zkemail/email-recovery
• Email-auth SDK (email-tx-builder)：https://github.com/zkemail/email-tx-builder