- 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](https://github.com/miksi-labs/miksi-core/blob/master/circuits/deposit.circom).
### 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](https://github.com/miksi-labs/miksi-core/blob/master/circuits/withdraw.circom).