Zircuit
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About
Zircuit is a universal Rollup that aims to use zk proofs in the future. It is based on the Optimism Bedrock architecture, employing AI to identify and stop malicious transactions at the sequencer level.
Badges
About
Zircuit is a universal Rollup that aims to use zk proofs in the future. It is based on the Optimism Bedrock architecture, employing AI to identify and stop malicious transactions at the sequencer level.
Recategorisation
The project will be classified as "Other" due to its specific risks that set it apart from the standard classifications.
The project will move to Others because:
Consequence: projects without a proper proof system fully rely on single entities to safely update the state. A malicious proposer can finalize an invalid state, which can cause loss of funds.
2024 Jul 03 — 2025 Feb 21
2024 Jul 02 — 2025 Feb 20
The section shows the operating costs that L2s pay to Ethereum.
2024 Feb 21 — 2025 Feb 20
Funds can be stolen if
Funds can be frozen if
MEV can be extracted if
Sequencer failure
Self sequenceState validation
NoneCurrently the system permits invalid state roots. More details in project overview.
Exit window
NoneThere is no window for users to exit in case of an unwanted regular upgrade since contracts are instantly upgradable.
Proposer failure
Cannot withdrawOnly the whitelisted proposers can publish state roots on L1, so in the event of failure the withdrawals are frozen.
Zircuit is a Validity proofs (when available) ensure state correctness, but not DA
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. Currently proofs are optional and state (by default) is considered optimistically to be valid. Moreover, the system doesn’t check that the transactions applied to the state are the ones published by the sequencer.
Funds can be stolen if the published state is invalid and the Challenger does not react during the 4h finalization window.
All data required for proofs is published on chain
All the data that is used to construct the system state is published on chain in the form of cheap blobs or calldata. This ensures that it will be available for enough time.
- Derivation: Batch submission - OP Mainnet specs
- BatchInbox - address
- OptimismPortal.sol - source code, depositTransaction function
EthereumThe system has a centralized operator
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.
Users can force any transaction
Because the state of the system is based on transactions submitted on the underlying host chain and anyone can submit their transactions there it allows the users to circumvent censorship by interacting with the smart contract on the host chain directly.
Regular messaging
The user initiates L2->L1 messages by submitting a regular transaction on this chain. When the block containing that transaction is settled, the message becomes available for processing on L1. The process of block finalization takes a challenge period of 4h to complete.
Funds can be frozen if the centralized validator goes down. Users cannot produce blocks themselves and exiting the system requires new block production (CRITICAL).
Forced messaging
If the user experiences censorship from the operator with regular L2->L1 messaging they can submit their messages directly on L1. The system is then obliged to service this request or halt all messages, including forced withdrawals from L1 and regular messages initiated on L2. Once the force operation is submitted and if the request is serviced, the operation follows the flow of a regular message.
EVM compatible smart contracts are supported
OP stack chains are pursuing the EVM Equivalence model. No changes to smart contracts are required regardless of the language they are written in, i.e. anything deployed on L1 can be deployed on L2.
Ethereum
Roles:
Allowed to challenge or delete state roots proposed by a Proposer.
Allowed to pause deposits and withdrawals.
Allowed to post new state roots of the current layer to the host chain.
Allowed to commit transactions from the current layer to the host chain.
Actors:
- A Multisig with 2 / 5 threshold.
- A Guardian.
- Is allowed to interact with ZircuitSuperchainConfig - manage roles including the guardian role.
- A Multisig with 6 / 8 threshold.
- Can act on behalf of ProxyAdmin.
- A Challenger.
- Is allowed to interact with SystemConfig - it can update the preconfer address, the batch submitter (Sequencer) address and the gas configuration of the system.
- Can upgrade the implementation of OptimismPortal, L1CrossDomainMessenger, SystemConfig, Verifier, ZircuitSuperchainConfig, L2OutputOracle, L1ERC721Bridge, OptimismMintableERC20Factory - acting via ProxyAdmin.
- Can upgrade the implementation of L1StandardBridge - upgrading the bridge implementation can give access to all funds escrowed therein - acting via ProxyAdmin.
Ethereum
The main entry point to deposit funds from host chain to this chain. It also allows to prove and finalize withdrawals. This contract stores the following tokens: ETH.
Sends messages from host chain to this chain, and relays messages back onto host chain. In the event that a message sent from host chain to this chain is rejected for exceeding this chain’s epoch gas limit, it can be resubmitted via this contract’s replay function.
The main entry point to deposit ERC20 tokens from host chain to this chain. This contract can store any token.
- Can be used to upgrade implementation of OptimismPortal, L1CrossDomainMessenger, SystemConfig, Verifier, ZircuitSuperchainConfig, L2OutputOracle, L1ERC721Bridge, OptimismMintableERC20Factory.
- Can be used to upgrade implementation of L1StandardBridge - upgrading the bridge implementation can give access to all funds escrowed therein.
This contract verifies ZK proofs (if provided). There is an intentional dummy backdoor allowing to call this contract without a proof.
This is NOT the shared SuperchainConfig contract of the OP stack Superchain but rather a local fork. It manages the PAUSED_SLOT, a boolean value indicating whether the local chain is paused, and access control for configuring actors who can pause and unpause the system.
Escrow for custom external tokens that use the canonical bridge for messaging but are governed externally. This contract stores the following tokens: wstETH.
Contains a list of proposed state roots which Proposers assert to be a result of block execution. Currently only the PROPOSER address can submit new state roots.
Used to bridge ERC-721 tokens from host chain to this chain.
A helper contract that generates OptimismMintableERC20 contracts on the network it’s deployed to. OptimismMintableERC20 is a standard extension of the base ERC20 token contract designed to allow the L1StandardBridge contracts to mint and burn tokens. This makes it possible to use an OptimismMintablERC20 as this chain’s representation of a token on the host chain, or vice-versa.
Value Secured is calculated based on these smart contracts and tokens:
Main entry point for users depositing ERC20 token that do not require custom gateway.
Main entry point for users depositing ETH.
custom wstETH Vault controlled by Lido governance, using the canonical bridge for messaging.
The current deployment carries some associated risks:
Funds can be stolen if a contract receives a malicious code upgrade. There is no delay on code upgrades (CRITICAL).
