Search

Search for projects by name

Re.al logoRe.al

Badges

About

Re.al is an Arbitrum Orbit stack L2 with AnyTrust data availability, focusing on Real World Assets.


Value Locked
$34.18 M11.4%
Canonically Bridged
$8.95 K
Externally Bridged
$3.74 M
Natively Minted
$30.42 M

  • Tokens
  • Daily UOPS
    0.0729.7%
  • 30D tx count
    252.83 K

  • Type
    Optimium
  • Purposes
    Universal, RWA
  • Sequencer failureState validationData availabilityExit windowProposer failure

    Badges

    About

    Re.al is an Arbitrum Orbit stack L2 with AnyTrust data availability, focusing on Real World Assets.


    Value Locked
    Activity
    Milestones & Incidents

    Re.al Mainnet Launch

    2024 May 15th

    Re.al launches its mainnet with some initial dapps deployed.

    Learn more

    Arcana Launch

    2024 May 15th

    Arcana launches their platform for rebasing, delta-neutral yields on re.al.

    Learn more
    Risk summary
    Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.
    Risk analysis
    Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.
    Sequencer failureState validationData availabilityExit windowProposer failure

    Sequencer failure

    Self sequence

    In the event of a sequencer failure, users can force transactions to be included in the project’s chain by sending them to L1. There is a 1d delay on this operation.

    State validation

    Fraud proofs (INT)

    Fraud proofs only allow 2 WHITELISTED actors watching the chain to prove that the state is incorrect. 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

    External (DAC)

    Proof construction relies fully on data that is NOT published onchain. There exists a Data Availability Committee (DAC) with a threshold of 1/2 that is tasked with protecting and supplying the data.

    Exit window

    None

    There is no window for users to exit in case of an unwanted regular upgrade since contracts are instantly upgradable.

    Proposer failure

    Self propose

    Anyone can become a Proposer after 12d 17h of inactivity from the currently whitelisted Proposers.

    Technology

    Data is not stored on chain

    Users transactions are not published onchain, but rather sent to external trusted parties, also known as committee members (DAC). Members of the DAC collectively produce a Data Availability Certificate (comprising BLS signatures from a quorum) guaranteeing that the data behind the new transaction batch will be available until the expiry period elapses (currently a minimum of two weeks). This signature is not verified by L1, however external Validators will skip the batch if BLS signature is not valid resulting. This will result in a fraud proof challenge if this batch is included in a consecutive state update. It is assumed that at least one honest DAC member that signed the batch will reveal tx data to the Validators if Sequencer decides to act maliciously and withhold the data. If the Sequencer cannot gather enough signatures from the DAC, it will “fall back to rollup” mode and by posting the full data directly to the L1 chain. The current DAC threshold is 1 out of 2.

    • Funds can be lost if the external data becomes unavailable (CRITICAL).

    • Users can be censored if the committee restricts their access to the external data.

    1. Inside AnyTrust - Arbitrum documentation
    Learn more about the DA layer here: Re.al DAC logoRe.al DAC
    State validation
    A diagram of the state validation
    A diagram of the state validation

    Updates 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.


    State root proposals

    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 12s. 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).

    1. How is fraud proven - Arbitrum documentation FAQ
    Challenges

    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.

    1. Fraud Proof Wars: Arbitrum Classic
    Fast confirmations

    Whitelisted validators can fast-confirm state-roots after the initial 12s minimum assertion period has passed on a state root and skip the 6d 8h challenge period. This finalizes the fast-confirmed state root an permits withdrawals based on it.

    • Funds can be stolen if validators with the 'fast-confirmer' permission finalize a malicious state root before the challenge period has passed (CRITICAL).

    1. Fast withdrawals for AnyTrust chains - Arbitrum documentation
    Operator

    The 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.

    1. Sequencer - Arbitrum documentation

    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.

    1. SequencerInbox.sol - Etherscan source code, forceInclusion function
    2. Sequencer Isn’t Doing Its Job - Arbitrum documentation
    Withdrawals

    Regular exit

    The user initiates the withdrawal by submitting a regular transaction on this chain. When the block containing that transaction is finalized the funds become available for withdrawal on L1. The process of block finalization usually takes several days to complete. Finally the user submits an L1 transaction to claim the funds. This transaction requires a merkle proof.

    1. Transaction lifecycle - Arbitrum documentation
    2. L2 to L1 Messages - Arbitrum documentation
    3. Mainnet for everyone - Arbitrum Blog

    Tradeable Bridge Exit

    When a user initiates a regular withdrawal a third party verifying the chain can offer to buy this withdrawal by paying the user on L1. The user will get the funds immediately, however the third party has to wait for the block to be finalized. This is implemented as a first party functionality inside Arbitrum’s token bridge.

    1. Tradeable Bridge Exits - Arbitrum documentation

    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.

    Other considerations

    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.

    1. Inside Arbitrum Nitro
    Permissions

    The system uses the following set of permissioned addresses:

    Sequencer EOA 2

    Can submit transaction batches or commitments to the SequencerInbox contract on the host chain.

    Validator/Proposer EOA 3

    Can propose new state roots (called nodes) and challenge state roots on the host chain.

    AnyTrust FastConfirmer EOA 3

    Can finalize a state root before the challenge period has passed. This allows withdrawing from the bridge based on the state root.

    GelatoMultisig 0xBeA2…9Bbb
    • A Gnosis Safe with 4 / 8 threshold.
    • Can act on behalf of UpgradeExecutor.
    • Can change the configuration of RollupProxy (acting via UpgradeExecutor) - Pause and unpause and set important roles and parameters in the system contracts.
    • Can upgrade the implementation of ChallengeManager, ERC20Bridge, L1OrbitGatewayRouter, ERC20RollupEventInbox, SequencerInbox, ERC20Outbox, UpgradeExecutor, ERC20Inbox, L1OrbitERC20Gateway (acting via ProxyAdmin, UpgradeExecutor).
    • Can upgrade the implementation of RollupProxy (acting via UpgradeExecutor).

    Used in:

    Those are the participants of the GelatoMultisig.

    RealStrategiesMultisig 0xD47E…23d4
    • A Gnosis Safe with 4 / 5 threshold.
    • Can change the configuration of RealVault - can manage asset strategies and fees for the user’s funds backing reETH.
    • Can upgrade the implementation of RealVault.

    Those are the participants of the RealStrategiesMultisig.

    RealFastConfirmerMultisig 0x118A…3A50
    RealFastConfirmerMultisig participants (1) EOA 3

    Those are the participants of the RealFastConfirmerMultisig.

    A Sequencer - Can submit transaction batches or commitments to the SequencerInbox contract on the host chain.

    Can upgrade the implementation of Bridger.

    Smart contracts
    A diagram of the smart contract architecture
    A diagram of the smart contract architecture

    The system consists of the following smart contracts on the host chain (Ethereum):

    OneStepProverHostIo 0x0003…68C4

    One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

    Implementation used in:

    OneStepProverMemory 0x1cD7…D7fB

    One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

    Implementation used in:

    ValidatorUtils 0x2b0E…66aF

    Implementation used in:

    OneStepProver0 0x2dCC…22b5

    One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

    Implementation used in:

    Contract that allows challenging state roots. Can be called through the RollupProxy by Validators or the UpgradeExecutor.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    Escrow contract for the project’s gas token (Can be different from ETH). Keeps a list of allowed Inboxes and Outboxes for canonical bridge messaging. This contract stores the following tokens: ETH.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    This routing contract maps tokens to the correct escrow (gateway) to be then bridged with canonical messaging.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    SwapManager 0x4AC3…c335

    Performs swaps via Curve or UniswapV3 to serve instant withdrawals from the reETH RealVault.

    Helper contract sending configuration data over the bridge during the systems initialization.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    A sequencer (registered in this contract) can submit transaction batches or commitments here.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    StrategyManager 0x5Cba…DdD8

    A gateway contract that manages strategies for assets that are deposited to the AssetsVault. From a user PoV this happens when bridging to the L2.

    LidoStEthStrategy 0x679D…31f6

    This contract stores the following tokens: stETH.

    Facilitates L2 to L1 contract calls: Messages initiated from L2 (for example withdrawal messages) eventually resolve in execution on L1.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    OneStepProofEntry 0x8Faa…4DaC

    One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

    Implementation used in:

    ProxyAdmin 0xB032…80f1

    Can be used to upgrade implementation of ChallengeManager, ERC20Bridge, L1OrbitGatewayRouter, ERC20RollupEventInbox, SequencerInbox, ERC20Outbox, UpgradeExecutor, ERC20Inbox, L1OrbitERC20Gateway.

    A Routing contract to the standard orbit stack bridge of the L2.

    Can be upgraded by:

    Upgrade delay: No delay

    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).

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    OneStepProverMath 0xCf4b…A6eD

    One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

    Implementation used in:

    • Can act on behalf of ProxyAdmin.
    • Can be used to configure RollupProxy - Pause and unpause and set important roles and parameters in the system contracts.
    • Can be used to upgrade implementation of RollupProxy.
    • Central contract defining the access control permissions for upgrading the system contract implementations.
    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    Facilitates sending L1 to L2 messages like depositing ETH, but does not escrow funds.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    AssetsVault 0xf985…2294

    This escrow contract receives ETH that users bridge to Re.al L2. This ETH is then converted to yielding assets using the StrategyManager.

    RealVault 0xFC1d…A5e1

    This contract is responsible for managing deposit, withdrawal, and settlement processes for the assets backing reETH using the ERC4626 (tokenized vault) standard.

    Can be upgraded by:

    Upgrade delay: No delay

    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.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    Value Locked is calculated based on these smart contracts and tokens:

    Default Gateway for non-native tokens. On depositing, a generic ‘wrapped’ version of the escrowed token is minted on the L2.

    Implementation used in:

    Contract managing Inboxes and Outboxes. It escrows ETH sent to L2.

    Can be upgraded by:

    Upgrade delay: No delay

    Implementation used in:

    Escrow for stETH 0x679D…31f6

    This contract escrows the stETH that was deposited to mint reETH.

    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).