ZCross connects web2 to the base layer of Blockchain e.g Ethereum through the on-chain smart contracts. Together, these ensure web2 state change and execution are trustworthy and allow users to pass assets and messages between web2 and web3.
The on-chian verify contract receives web2 state roots and batch from ZKCross dedicated Sequencer. It stores state roots in the Ethereum state and batch data to ZKCross DA. This provides data availability for web2 batches and leverages the security of Ethereum to ensure that any indexers can reconstruct web2 batches. Once a batch proof establishing the validity of a web2 batch has been verified by the verification contract, the corresponding web2 batch is considered finalized.
The on-chain contracts deployed on the Ethereum allow users to pass arbitrary messages between web2 and web3 code logics. On top of this message-passing protocol, we have also built a trustless fusion protocol to allow web2 and web3 applications to communicate in both directions.
Settlement protocol is a protocol between the contract and the application on some of the program inputs. Settlement can include token & NFT transfer, on-chain data update, and proof incentive. payment. The settlement won't fail if the proof verification succeeds.