RARI Chain
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About
RARI Chain embeds royalties on the node level to guarantee royalty payments. A secure, low-cost, decentralized Ethereum L3 blockchain powered by Arbitrum.
Badges
About
RARI Chain embeds royalties on the node level to guarantee royalty payments. A secure, low-cost, decentralized Ethereum L3 blockchain powered by Arbitrum.
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 sufficiently decentralized set of challengers rely on few entities to safely update the state. A small set of challengers can collude with the proposer to finalize an invalid state, which can cause loss of funds.
RARI integrates Espresso sequencer
2025 Jan 30th
RARI is the first chain to integrate Espresso TEE sequencer.
RARI integrates Celestia Blobstream
2024 Dec 19th
RARI is the first chain to integrate Celestia Blobstream DA bridge.
Arbitrum OneFunds can be stolen if
Funds can be lost if
MEV can be extracted if
| SEQUENCER FAILURE | STATE VALIDATION | DATA AVAILABILITY | EXIT WINDOW | PROPOSER FAILURE | |
| Arbitrum One L2 | Self sequence | Fraud proofs (INT) | Onchain | 7d | Self propose |
| RARI Chain L3 • Individual | Self sequence | Fraud proofs (INT) | External | None | Self propose |
| RARI Chain L3 • Combined | Self sequence | Fraud proofs (INT) | External | None | Self propose |
Sequencer failure
Self sequenceState validation
Fraud proofs (INT)No actor outside of the single Proposer can submit fraud proofs. Interactive proofs (INT) require multiple transactions over time to resolve. The challenge protocol can be subject to delay attacks. There is a 6d 8h challenge period.
Data availability
ExternalProof construction and state derivation fully rely on data that is posted on Celestia. Sequencer tx roots are checked against the Blobstream bridge data roots, signed off by Celestia validators.
Exit window
NoneThere is no window for users to exit in case of an unwanted regular upgrade since contracts are instantly upgradable.
Proposer failure
Self proposeAnyone can become a Proposer after 25d 10h of inactivity from the currently whitelisted Proposers.
Arbitrum OneData is posted to Celestia
Transactions roots are posted onchain and the full data is posted on Celestia. The blobstream bridge is used to verify attestations from the Celestia validator set that the data is indeed available.
Funds can be lost if the sequencer posts an unavailable transaction root (CRITICAL).
Funds can be lost if the data is not available on the external provider (CRITICAL).
CelestiaUpdates to the system state can be proposed and challenged by a set of whitelisted validators. If a state root passes the challenge period, it is optimistically considered correct and made actionable for withdrawals.
Whitelisted validators propose state roots as children of a previous state root. A state root can have multiple conflicting children. This structure forms a graph, and therefore, in the contracts, state roots are referred to as nodes. Each proposal requires a stake, currently set to 0.1 ETH, that can be slashed if the proposal is proven incorrect via a fraud proof. Stakes can be moved from one node to one of its children, either by calling stakeOnExistingNode or stakeOnNewNode. New nodes cannot be created faster than the minimum assertion period by the same validator, currently set to 15m. The oldest unconfirmed node can be confirmed if the challenge period has passed and there are no siblings, and rejected if the parent is not a confirmed node or if the challenge period has passed and no one is staked on it.
Funds can be stolen if none of the whitelisted verifiers checks the published state. Fraud proofs assume at least one honest and able validator (CRITICAL).
A challenge can be started between two siblings, i.e. two different state roots that share the same parent, by calling the startChallenge function. Validators cannot be in more than one challenge at the same time, meaning that the protocol operates with partial concurrency. Since each challenge lasts 6d 8h, this implies that the protocol can be subject to delay attacks, where a malicious actor can delay withdrawals as long as they are willing to pay the cost of losing their stakes. If the protocol is delayed attacked, the new stake requirement increases exponentially for each challenge period of delay. Challenges are played via a bisection game, where asserter and challenger play together to find the first instruction of disagreement. Such instruction is then executed onchain in the WASM OneStepProver contract to determine the winner, who then gets half of the stake of the loser. As said before, a state root is rejected only when no one left is staked on it. The protocol does not enforces valid bisections, meaning that actors can propose correct initial claim and then provide incorrect midpoints.
Arbitrum OneThe system has a centralized sequencer
While forcing transaction is open to anyone the system employs a privileged sequencer that has priority for submitting transaction batches and ordering transactions.
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. After a delay of 1d in which a Sequencer has failed to include a transaction that was directly posted to the smart contract, it can be forcefully included by anyone on the host chain, which finalizes its ordering.
Espresso TEE sequencer
Rari integrates with Espresso sequencing. In addition to providing regular pre-confirmations, the sequencer publishes blocks to the Espresso Network. The integration expects the transaction batch poster to run inside a Trusted Execution Environment (TEE), and it is programmed to verify batch inclusion in a Espresso Network block before publishing it to the host chain. However, the confirmations provided by Espresso Network are additive, and the batch poster can skip Espresso inclusion checks should the Espresso Network be down or unavailable. To ensure the batch poster is running inside a TEE, the sequencer inbox contract on the host chain was updated so that the data posting function also includes a TEE attestation as input, a “quote”, that is verified onchain by the EspressoTEEVerifier for each batch transaction. The verifier checks the quote signature originates from inside the TEE and reverts if unsuccessful.
Withdrawals can be delayed if the owner of EspressoTEEVerifier updates the contract verification values (mrEnclave, mrSigner) and it is no longer possible to verify the TEE quote.
Arbitrum OneRegular messaging
Autonomous exit
Users can (eventually) exit the system by pushing the transaction on L1 and providing the corresponding state root. The only way to prevent such withdrawal is via an upgrade.
EVM compatible smart contracts are supported
Arbitrum One uses Nitro technology that allows running fraud proofs by executing EVM code on top of WASM.
Funds can be lost if there are mistakes in the highly complex Nitro and WASM one-step prover implementation.
Arbitrum One
Roles:
Can submit transaction batches or commitments to the SequencerInbox contract on the host chain.
Can propose new state roots (called nodes) and challenge state roots on the host chain.
Actors:
- A Multisig with 3 / 4 threshold.
- Can act on behalf of UpgradeExecutor.
- Is allowed to interact with RollupProxy - Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability, DACs and the fastConfirmer role, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes - acting via UpgradeExecutor.
- Can upgrade the implementation of UpgradeExecutor, Bridge, L1GatewayRouter, Inbox, RollupEventInbox, L1ERC20Gateway, L1CustomGateway, Outbox, SequencerInbox, ChallengeManager - acting via ProxyAdmin, UpgradeExecutor.
- Can upgrade the implementation of RollupProxy - acting via UpgradeExecutor.
Used in:
- Is allowed to interact with SequencerInbox - Add/remove batchPosters (Sequencers).
- A Sequencer - Can submit transaction batches or commitments to the SequencerInbox contract on the host chain.
The project uses Celestia with the Blobstream DA Bridge that consist of the following permissions on the Arbitrum One:
- A Multisig with 4 / 6 threshold.
- Is allowed to interact with Blobstream - can freeze the bridge contract and update the list of authorized relayers.
- Can upgrade the implementation of Blobstream.
- A Multisig with 3 / 4 threshold.
- Is allowed to interact with SuccinctGateway - can renounce and transfer ownership, add and remove default prover, set fee vault, and recover stuck ETH.
Is allowed to interact with SuccinctGatewaySP1 - can verify proofs for the header range [latestBlock, targetBlock] proof.
Is allowed to interact with Blobstream - it is a ‘Relayer’ and can call commitHeaderRange() to commit block ranges. Since adding and removing Relayers emits no events, there can be more relayers than are presented here.
Is allowed to interact with Blobstream - it is a ‘Relayer’ and can call commitHeaderRange() to commit block ranges. Since adding and removing Relayers emits no events, there can be more relayers than are presented here.
Arbitrum One
Can be used to upgrade implementation of UpgradeExecutor, Bridge, L1GatewayRouter, Inbox, RollupEventInbox, L1ERC20Gateway, L1CustomGateway, Outbox, SequencerInbox, ChallengeManager.
One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.
- Central contract defining the access control permissions for upgrading the system contract implementations.
- Can act on behalf of ProxyAdmin.
- Can be used to interact with RollupProxy - Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability, DACs and the fastConfirmer role, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes.
- Can be used to upgrade implementation of RollupProxy.
Implementation used in:
One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.
This routing contract maps tokens to the correct escrow (gateway) to be then bridged with canonical messaging.
Central contract for the project’s configuration like its execution logic hash (wasmModuleRoot) and addresses of the other system contracts. Entry point for Proposers creating new Rollup Nodes (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both held by the Validators).
Helper contract sending configuration data over the bridge during the systems initialization.
One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.
The QuoteVerifier contract is used by the EspressoTEEVerifier to verify the validity of the TEE quote.
Escrows deposited ERC-20 assets for the canonical Bridge. Upon depositing, a generic token representation will be minted at the destination. Withdrawals are initiated by the Outbox contract. This contract can store any token.
Escrows deposited assets for the canonical bridge that are externally governed or need custom token contracts with e.g. minting rights or upgradeability. This contract can store any token.
One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.
This contract implements view only utilities for validators.
Implementation used in:
The Espresso TEE sequencer (registered in this contract) can submit transaction batches or commitments here. This version of the SequencerInbox also supports commitments to data that is posted to Celestia.
Contract that allows challenging state roots. Can be called through the RollupProxy by Validators or the UpgradeExecutor.
One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine. This version uses the Blobstream DA bridge as source of truth for the DA referenced by the fault proof.
The Espresso TEE verifier is used by the SequencerInbox contract to verify the batch attestations signed by the TEE.
The project uses Celestia with the Blobstream DA Bridge that consist of the following contracts on the Arbitrum One:
Users could interact with this contract to request proofs onchain, emitting a RequestCall event for off-chain provers to consume. Now deprecated, SP1 is used instead.
The source code of this contract is not verified on Etherscan.
Value Secured is calculated based on these smart contracts and tokens:
Main entry point for users depositing ERC20 tokens. Upon depositing, on L2 a generic, “wrapped” token will be minted.
Main entry point for users depositing ERC20 tokens that require minting custom token on L2.
Contract managing Inboxes and Outboxes. It escrows ETH sent to L2.
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).