The ZKSpace platform consists of three main parts: a Layer 2 AMM DEX utilizing ZK-Rollups technology ZKSwap v3, a payment service called ZKSquare, and an NFT marketplace called ZKSea.
ZK-SNARKS are zero knowledge proofs that ensure state correctness, but require trusted setup.
All of the data needed for proof construction is published on chain.
The code that secures the system can be changed arbitrarily but users have some time to react even if the permissioned operator is censoring.
Users can force the sequencer to include a withdrawal transaction by submitting a request through L1. If the sequencer censors or is down for for more than 3d, users can use the exit hatch to withdraw their funds.
Users are able to trustlessly exit by submitting a zero knowledge proof of funds.
Each update to the system state must be accompanied by a ZK Proof that ensures that the new state was derived by correctly applying a series of valid user transactions to the previous state. These proofs are then verified on Ethereum by a smart contract.
Despite their production use ZK-SNARKs are still new and experimental cryptography. Cryptography has made a lot of advancements in the recent years but all cryptographic solutions rely on time to prove their security. In addition ZK-SNARKs require a trusted setup to operate.
Funds can be stolen if the cryptography is broken or implemented incorrectly.
All the data that is used to construct the system state is published on chain in the form of cheap calldata. This ensures that it will always be available when needed.
The operator is the only entity that can propose blocks. A live and trustworthy operator is vital to the health of the system.
MEV can be extracted if the operator exploits their centralized position and frontruns user transactions.
Force exit allows the users to escape censorship by withdrawing their funds. The system allows users to force the withdrawal of funds by submitting a request directly to the contract on-chain. The request must be served within a defined time period. If this does not happen, the system will halt regular operation and permit trustless withdrawal of funds.
Users can be censored if the operator refuses to include their transactions. However, there exists a mechanism to independently exit the system.
The user initiates the withdrawal by submitting a regular transaction on this chain. When the block containing that transaction is proven the funds become available for withdrawal on L1. Finally the user submits an L1 transaction to claim the funds. This transaction does not require a merkle proof.
If the user experiences censorship from the operator with regular exit they can submit their withdrawal requests directly on L1. The system is then obliged to service this request. Once the force operation is submitted and if the request is serviced, the operation follows the flow of a regular exit.
If enough time passes and the forced exit is still ignored the user can put the system into Exodus Mode, disallowing further state updates. In that case everybody can withdraw by submitting a zero knowledge proof of their funds with their L1 transaction.
Funds can be lost if the user is unable to generate the non-trivial zk proof for exodus withdraw.
This address is the master of Upgrade Gatekeeper contract, which is allowed to perform upgrades for Governance, Verifier, VerifierExit, PairManager, ZkSeaNFT and ZkSync contracts.
This actor is allowed to propose, revert and execute L2 blocks on L1. A list of active validators is kept inside Governance contract and can be updated by zkSpace Admin.
The main Rollup contract. Operator commits blocks, provides zkProof which is validated by the Verifier contract and process withdrawals (executes blocks). Users deposit ETH and ERC20 tokens. This contract defines the upgrade delay in the UPGRADE_NOTICE_PERIOD constant that is currently set to 8 days. This contract can store any token.
Can be upgraded by: zkSpace Admin
This is the contract that implements the upgrade mechanism for Governance, Verifier and ZkSync. It relies on the ZkSync contract to enforce upgrade delays.
The current deployment carries some associated risks:
Funds can be stolen if a contract receives a malicious code upgrade. There is a 8d delay on code upgrades.