miksi

From Esperanto, miksi (miks·i): to mingle, to blend, to mix, to shuffle

Warning: This repository is in a very early stage.

Circuits tests

npm run test-circuits

Smart Contracts tests

npm run test-sc

Compile circom circuit & generate Groth16 verifier contract

./compile-circuits.sh

Spec draft

Deposit

• user generates a random secret & nullifier
• computes the commitment, which is the Poseidon hash: commitment = H(coinCode, amount, secret, nullifier), where:
  • coinCode: code that specifies which currency is being used (0==ETH)
  • amount: the amount to be deposited
  • secret: random, private
  • nullifier: random
• get all the commitments from the SmartContract
• build the MerkleTree with the getted commitments
• add the new computed commitment into the MerkleTree
• generate zkSNARK proof, where is proving:
  • prover knows the secret & nullifier for the commitment
  • the transition from RootOld (the current one in the Smart Contract) to RootNew has been done following the rules (only one addition, no deletion)
• user sends ETH to the smart contract deposit call, together with the zkProof data

Deposit circuit can be found here.

Withdraw

• user gets all the commitments from the SmartContract
• build the MerkleTree with the getted commitments
• generate the siblings for the commitment of which the user knows the secret & nullifier
• generate zkSNARK proof, where is proving: - user knows a secret for a public nullifier - which commitment is in the MerkleTree - which MerkleTree root is the one that knows the SmartContract
• if the zkProof verification passes, and the nullifier was not already used, the Smart Contract sends the ETH to the specified address

Withdraw circuit can be found here.