zkLink Nova
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About
zkLink Nova is a Layer 3 zkEVM Validium network leveraging ZK Stack that allows for scattered assets across Ethereum Layer 2s to be aggregated for interoperable trade and transactions.
Badges
About
zkLink Nova is a Layer 3 zkEVM Validium network leveraging ZK Stack that allows for scattered assets across Ethereum Layer 2s to be aggregated for interoperable trade and transactions.
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 data availability bridge fully rely on single entities (the sequencer) to honestly rely available data roots on Ethereum. A malicious sequencer can collude with the proposer to finalize an unavailable state, which can cause loss of funds.
Learn more about the recategorisation here.
LineaFunds can be stolen if
Funds can be lost if
Users can be censored if
MEV can be extracted if
| SEQUENCER FAILURE | STATE VALIDATION | DATA AVAILABILITY | EXIT WINDOW | PROPOSER FAILURE | |
| Linea L2 | No mechanism | ZK proofs (SN) | Onchain | None | Cannot withdraw |
| zkLink Nova L3 • Individual | Enqueue via L2 | ZK proofs (ST, SN) | External | None | Cannot withdraw |
| zkLink Nova L3 • Combined | No mechanism | ZK proofs | External | None | Cannot withdraw |
Sequencer failure
No mechanismThere is no mechanism to have transactions be included if the sequencer is down or censoring.
State validation
ZK proofsZero knowledge cryptography is used to ensure state correctness. Proofs are first verified on Linea and finally on Ethereum.
Data availability
ExternalProof construction and state derivation rely fully on data that is ultimately NOT published on Ethereum.
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.
LineaZero knowledge STARK and SNARK cryptography is used
Despite their production use zkSTARKs and zkSNARKs proof systems are still relatively new, complex and they rely on the proper implementation of the polynomial constraints used to check validity of the Execution Trace. In addition zkSNARKs require a trusted setup to operate.
Funds can be lost if the proof system is implemented incorrectly.
Data is not stored on chain
The transaction data is not recorded on the Ethereum main chain.
Funds can be lost if the external data becomes unavailable (CRITICAL).
LineaThe system has a centralized operator
The validators are the only entities that can propose blocks and process transactions. Moreover, they are trusted to only relay valid messages using the fast path. Fast path messages are eventually checked against the slow path, and if they are invalid, the system halts.
MEV can be extracted if the operator exploits their centralized position and frontruns user transactions.
Funds can be lost if the operator relays invalid messages using the fast path (CRITICAL).
Users can force any transaction via L2
If a user is censored by L3 Sequencer, they can try to force transaction via L2 queue. Right now there is no mechanism that forces L3 Sequencer to include transactions from L2 queue in an L3 block.
Users can be censored if the operator refuses to include their transactions.
LineaForced exit
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 or halt all messages from L1, including all forced withdrawals and deposits. Once the force operation is submitted and if the request is serviced, the operation follows the flow of a regular exit.
Bridging from multiple chains
zkLink allows users to bridge assets from multiple chains, not just the base chain Linea. To do this, messages are sent through the canonical bridges of each respective chain to the main zkLink contract on Linea. To withdraw, state updates are relayed back to each chain with the respective canonical bridges. Since deposits in this way are processed quite slowly, the system allows validators to relay messages directly to the main zkLink contract in a trusted way. These messages are then checked against the slow path, and if they are invalid, the system eventually halts.
Funds can be lost if the canonical bridges of the secondary chains are compromised.
The system uses the following set of permissioned addresses:
A Gnosis Safe with 5 / 8 threshold. Admin of the main zkLink contract, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the LineaOwner.
Permissioned actors that can commit, prove and execute blocks. It can also “fast” relay messages to zkLink Nova without going through the canonical bridges, meaning it can potentially relay invalid messages and mint tokens out of thin air. In that case, since the system checks such messages against the slow path, after some time the system would halt.
The system consists of the following permissions on OP Mainnet:
Owner of the L1ERC20Bridge on OP Mainnet.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on OP Mainnet and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the OptimismOwner.
The system consists of the following permissions on Arbitrum One:
Owner of the L1ERC20Bridge on Arbitrum One.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on Arbitrum One and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the ArbitrumOwner.
The system consists of the following permissions on Base:
Owner of the L1ERC20Bridge on Base.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on Base and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the BaseOwner.
The system consists of the following permissions on Manta Pacific:
Owner of the L1ERC20Bridge on Manta Pacific.
Admin of the zkLink contract on Manta Pacific and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gaining access to all funds.
The system consists of the following permissions on Mantle:
Owner of the L1ERC20Bridge on Mantle.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on Mantle and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the MantleOwner.
The system consists of the following permissions on Scroll:
Owner of the L1ERC20Bridge on Scroll.
A Gnosis Safe with 5 / 7 threshold. Admin of the zkLink contract on Scroll and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the AdminMultisig.
The system consists of the following permissions on Blast:
Owner of the L1ERC20Bridge on Blast.
A Gnosis Safe with 6 / 8 threshold. Admin of the zkLink contract on Blast and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the BlastOwner.
The system consists of the following permissions on ZKsync Era:
Owner of the L1ERC20Bridge on ZKsync Era.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on ZKsync Era and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the EraOwner.
The system consists of the following permissions on Ethereum:
Owner of the L1ERC20Bridge on Ethereum.
A Gnosis Safe with 5 / 8 threshold. Admin of the zkLink contract on Ethereum and the ProxyAdmin, meaning it can upgrade the bridge implementation and potentially gain access to all funds.
Those are the participants of the EthereumOwner.
The system consists of the following smart contracts on the host chain (Linea):
Main entry point for depositing ERC20 tokens from Linea to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main contract of the system where blocks are committed, proven and executed. It syncs messages from secondary chains (“slow” path) and accepts “fast” forwarded requests from permissioned validators that are later cross-checked with the slow path. ETH coming from secondary chains are transferred and escrowed here. State roots are then synced back to the secondary chains. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the main zkLink contract and Linea’s message service.
Upgrade delay: No delay
Intermediary contract between the one of the validators and the ZKsync Era diamond that can delay block execution (ie withdrawals and other L3 --> L2 messages). Currently, the delay is set to 0s.
Implements ZK proof verification logic.
Upgrade delay: No delay
Intermediary governance contract with two roles and a customizable delay. This delay is only mandatory for transactions scheduled by the Owner role and can be set by the SecurityCouncil role. The SecurityCouncil role can execute arbitrary upgrade transactions immediately. Currently the delay is set to 0s and the SecurityCouncil role is not used.
The system consists of the following smart contracts on Ethereum:
Main entry point for depositing ERC20 tokens from Ethereum to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Ethereum and ETH escrow. Outgoing messages (like deposits) are sent through the EthereumL2Gateway which ultimately makes use of Ethereum’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Ethereum’s message service.
Upgrade delay: No delay
Contract storing the mapping between secondary chain bridges and acts as an intermediary to receive and relay messages to and from the main zkLink contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the LineaL2Gateway on Linea. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the MantaL2Gateway on Manta Pacific. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the MantleL2Gateway on Mantle. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the EraL2Gateway on ZKsync Era. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the ArbitrumL2Gateway on Arbitrum One. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the BlastL2Gateway on Blast. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the OptimismL2Gateway on OP Mainnet. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the BaseL2Gateway on Base. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
L1 counterpart receiving messages from the ScrollL2Gateway on Scroll. It redirects them to the Arbitrator contract.
Upgrade delay: No delay
The system consists of the following smart contracts on OP Mainnet:
Main entry point for depositing ERC20 tokens from OP Mainnet to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on OP Mainnet and ETH escrow. Outgoing messages (like deposits) are sent through the OptimismL2Gateway which ultimately makes use of OP Mainnet’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and OP’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Arbitrum One:
Main entry point for depositing ERC20 tokens from Arbitrum One to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Arbitrum One and ETH escrow. Outgoing messages (like deposits) are sent through the ArbitrumL2Gateway which ultimately makes use of Arbitrum One’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Arbitrum’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Base:
Main entry point for depositing ERC20 tokens from Base to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Base and ETH escrow. Outgoing messages (like deposits) are sent through the BaseL2Gateway which ultimately makes use of Base’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Base’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Manta Pacific:
Main entry point for depositing ERC20 tokens from Manta Pacific to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Manta Pacific and ETH escrow. Outgoing messages (like deposits) are sent through the MantaPacificL2Gateway which ultimately makes use of Manta Pacific’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Manta Pacific’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Mantle:
Main entry point for depositing ERC20 tokens from Mantle to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Mantle and ETH escrow. Outgoing messages (like deposits) are sent through the MantleL2Gateway which ultimately makes use of Mantle’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Mantle’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Scroll:
Main entry point for depositing ERC20 tokens from Scroll to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract.
Upgrade delay: No delay
Main messaging contract on Scroll and ETH escrow. Outgoing messages (like deposits) are sent through the ScrollL2Gateway which ultimately makes use of Scroll’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts.
Upgrade delay: No delay
High level interface between the local zkLink contract and Scroll’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on Blast:
Main entry point for depositing ERC20 tokens from Blast to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on Blast and ETH escrow. Outgoing messages (like deposits) are sent through the BlastL2Gateway which ultimately makes use of Blast’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
High level interface between the local zkLink contract and Blast’s message service.
Upgrade delay: No delay
The system consists of the following smart contracts on ZKsync Era:
Main entry point for depositing ERC20 tokens from ZKsync Era to zkLink Nova. Outgoing messages and incoming withdrawal validation is delegated to the zkLink contract. This contract can store any token.
Upgrade delay: No delay
Main messaging contract on ZKsync Era and ETH escrow. Outgoing messages (like deposits) are sent through the ZKsync2L2Gateway which ultimately makes use of ZKsync Era’s canonical messaging bridge to reach the Arbitrator on L1. Only whitelisted validators can sync messages with zkLink Nova, which also transfer the ETH to it via the respective canonical bridges. Incoming messages (like withdrawals) are validated on Linea first and then sent to this contract through the same path. Whitelisted validators can also relay messages to zkLink without going through the canonical bridge (fast path), which are later cross-checked with the slow path. If the check fails, the system halts. This contract stores the following tokens: ETH.
Upgrade delay: No delay
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).