Public and secret fields
The transaction sent to the zkBob contract contains the following fields:
- Account nullifier - protects from double-spending, if the nullifier already exists the transaction is not valid and will not be executed.
- Transaction commitment - transaction's subtree root hash
- Transfer index
- XP (energy) amount - for withdrawal transaction
- Token amount - a positive value for deposit transaction, negative for withdrawal.
- Transaction proof
- Merkle tree root after transaction inclusion
- Merkle tree proof
- Transaction specific fields (depending on transaction type)
- Memo block containing encrypted transaction details (accounts and notes)
- Deposit signature - for retrieving source account (exists in the deposit transaction only)
In general, a transaction sender must prepare all fields before submitting a tx to the contract. When using the relayer, the relayer should calculate proofs and send the transaction to the contract.
There are two parts to a transaction created by a sender - public and secret.
- 1.The public input containing encrypted transaction data and other fields which do not disclosure sender, receiver, internal transfer amount, etc.
- 2.The secret portion contains unencrypted data such as input and output accounts and notes, proofs, and EDDSA signature.
- The current Merkle tree root (before transaction processing by the contract)
- Input account nullifier
- Transaction commitment
- Delta value (a composition of the transaction index, token delta and energy delta)
- Memo block
- A set of unencrypted input\output account and notes for the transaction
- Input account and notes proofs
- Transaction signature
- Transaction verifier keyto verify signature