Summary Value Secured Activity Risk summary Risk analysis Stage Data availability State validation Upgrades & Governance Updates Operator Sequencing Withdrawals Other considerations Permissions Smart contracts

Muster

This project is archived and no longer maintained.

Critical contracts can be upgraded by an EOA which could result in the loss of all funds.

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About

Muster Network is an Arbitrum Orbit L3 gaming chain aiming to transform digital ownership for brands and games while managing blockchain infrastructure and security.

Total Value SecuredTVS

$17.54 K1.58%

Past day UOPSDaily UOPS

No data

Gas token

ETH

Type

Other

Purposes

Universal, Gaming

Host chain

Arbitrum One

Chain ID

4078

Tokens breakdown

Value secured breakdown

0.00% with additional trust assumptions

View TVS breakdown

Sequencer failureState validationData availabilityExit windowProposer failure

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About

Muster Network is an Arbitrum Orbit L3 gaming chain aiming to transform digital ownership for brands and games while managing blockchain infrastructure and security.

Why is the project listed in others?

There are less than 5 external actors that can submit challenges

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.

There are less than 5 external actors that can attest data availability

Consequence: projects without a sufficiently decentralized data availability committee rely on few entities to safely attest data availability on Ethereum. A small set of entities can collude with the proposer to finalize an unavailable state, which can cause loss of funds.

Learn more about the recategorisation here.

Value Secured

View TVS breakdown

Exclude restricted RWA tokens

Total

Canonically BridgedCanonically Bridged ValueCanonical

Natively MintedNatively Minted TokensNative

Externally BridgedExternally Bridged ValueExternal

ETH & derivatives

Stablecoins

BTC & derivatives

Other

View TVS breakdown

Activity

Past Day UOPS

Past Day Ops count

Max. UOPS

Past day UOPS/TPS Ratio

Risk summary

There are 3 additional risks coming from the host chain

Arbitrum One

Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.

Risk analysis

The L3 risks depend on the individual properties of L3 and those of the host chain combined.

Critical contracts can be upgraded by an EOA which could result in the loss of all funds.

Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.

	SEQUENCER FAILURE	STATE VALIDATION	DATA AVAILABILITY	EXIT WINDOW	PROPOSER FAILURE
Arbitrum One L2	Self sequence	Fraud proofs (INT)	Onchain	None	Self propose
Muster L3 • Individual	Self sequence	Fraud proofs (INT)	External (DAC)	None	Self propose
Muster L3 • Combined	Self sequence	Fraud proofs (INT)	External (DAC)	None	Self propose

L2 & L3 individual risks

Sequencer failureState validationData availabilityExit windowProposer failure

L3 combined risks

Sequencer failureState validationData availabilityExit windowProposer failure

L3 combined risks

The information below reflects combined L2 & L3 risks.

Sequencer failure

Self sequence

In the event of a sequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. failure, users can force transactions to be included in the project’s chain by sending them to L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development.. There can be up to a 2d delay on this operation.

State validation

Fraud proofs (INT)

No actor outside of the single ProposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block. 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 30m challenge periodIn optimistic rollups, the window of time wherein network participants can assert that some fraud was included in a prior block. Most optimistic rollups currently specify a challenge window of 7 days. By extending the period, there is more time for participants to guard against fraud (invalid state transitions), but also more time until withdrawals gets enabled..

Data availability

External (DAC)

Proof construction relies fully on data that is NOT published onchain. There exists a Data Availability Committee (DAC)A set of members whose task is attesting and ensuring that the data is available for the public. An onchain DAC verifier checks that a threshold of signatures from the DAC members is reached before considering a data commitment as available and therefore valid to be used in the system. with a threshold of 1/1 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 upgrade since contracts are instantly upgradable.

Proposer failure

Self propose

Anyone can become a ProposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block. after 28d of inactivity from the currently whitelisted Proposers.

Stage

Muster is not even a

Stage 0

project.

The requirement for available node software is under review.

Learn more about Stages

Please keep in mind that these stages do not reflect project security, this is an opinionated assessment of project maturity based on subjective criteria, created with a goal of incentivizing projects to push toward better decentralization. Each team may have taken different paths to achieve this goal.

Data availability

Set of parties responsible for signing and attesting to the availability of data.

6.1

Risk analysis

Economic security

None

There are no onchain assets at risk of being slashed in case of a data withholding attack, and the committee members are not publicly known.

Fraud detection

None

There is no fraud detection mechanism in place. A data withholding attack can only be detected by nodes downloading the full data from the DA layerAn infrastructure that is used to make publish data so that it's available to the public. They take the form of Data Availability Committees (DACs) or blockchains. Not to confuse with the layer responsible with ordering, since ordering and DA can be separated..

Committee security

1/1

The committee does not meet basic security standards, either due to insufficient size, lack of member diversity, or poorly defined threshold parameters. The system lacks an effective DA bridgeSystem that verifies that data has been made available. It takes the form of a smart contract verifying a consensus or, if the data is verified directly by either downloading the full data or sampling, of an enshrined bridge. and it is reliant on the assumption of an honest sequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs., creating significant risks to data integrity and availability.

Upgradeability

No delay

There is no delay in the upgradeabilityThe ability for rollup smart contracts and parameters used in a rollup to be updated by holders of an admin key. Upgradeability represents a vector of risk for users, and should be decentralized and combined with time delays for greater security guarantees. of the bridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge.. Users have no time to exit the system before the bridge implementation update is completed.

Relayer failure

No mechanism

The relayer role is permissioned, and the DA bridgeSystem that verifies that data has been made available. It takes the form of a smart contract verifying a consensus or, if the data is verified directly by either downloading the full data or sampling, of an enshrined bridge. does not have a Security CouncilA Security Council is a sufficiently decentralized set of members that is able to upgrade a system. A properly set up Security Council consists of at least 8 members with a threshold greater than 75%. What 'sufficiently decentralized' means is fundamentally subjective and L2BEAT evaluates each case individually. A Security Council is allowed to instantly upgrade Stage 1 rollups. or a governance mechanism to propose new relayers. In case of relayer failure, the DA bridge will halt and be unable to recover without the intervention of a centralized entity.

6.2

Technology

Architecture

Anytrust architecture

The DAC uses a data availabilityThe property of a rollup's data being reachable by any node retrieving the data that were rolled up and executed to reach the proposed state. Data availability (DA), specifically decoupling it from the rollup nodes themselves, is one of the preeminent factors which allows a rollup to scale securely. A rollup is faced with a decision of what to use as a DA layer to guarantee that any node can retrieve this data--permissionlessly under any circumstance. For this reason, using Ethereum for DA currently provides the strongest security guarantees. If data is stored somewhere other than a permissionless L1, then the project is not a rollup, but rather a validium or an optimium. solution built on the AnyTrust protocol. It is composed of the following components:

SequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. Inbox: Main entry point for the Sequencer submitting transaction batches.
Data Availability Committee (DAC)A set of members whose task is attesting and ensuring that the data is available for the public. An onchain DAC verifier checks that a threshold of signatures from the DAC members is reached before considering a data commitment as available and therefore valid to be used in the system.: A group of members responsible for storing and providing data on demand.
Data Availability Certificate (DACert): A commitment ensuring that data blobsThe data that a rollup publishes to its L1/data availability (DA) layer. They consist of the L2 transactions that are rolled up, along with some metadata. Blobs are introduced as a new transaction type within Ethereum with EIP-4844, and has rollup scaling specifically in mind. Blobs persist on Ethereum’s Beacon Chain ephemerally. are available without needing full data posting on the L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. chain.

Committee members run servers that support APIs for storing and retrieving data blobs. The Sequencer API allows the rollupA blockchain that inherits consensus and data availability from another blockchain called L1. Rollups enable trust minimized bridges with the base layer via proof systems, either optimistic or zero-knowledge. A rollup without a bridge, or without considering the bridge, is called a sovereign rollup. Sequencer to submit data blobs for storage, while the REST API enables anyone to fetch data by hashA fixed-length fingerprint of variable-size input, produced by a hash function.. When the Sequencer produces a data batch, it sends the batch along with an expiration time to Committee members, who store it and sign it. Once enough signatures are collected, the Sequencer aggregates them into a valid DACert and posts it to the L1 chain inbox. If the Sequencer fails to collect enough signatures, it falls back to posting the full data to the L1 chain as calldata.

A DACert includes a hash of the data blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over., an expiration time, and proof that the required threshold of Committee members have signed off on the data. The proof consists of a hash of the Keyset used in signing, a bitmap indicating which members signed, and a BLS aggregated signature. L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups. nodes reading from the sequencer inbox verify the certificate’s validity by checking the number of signers, the aggregated signature, and that the expiration time is at least two weeks ahead of the L2 timestamp. If the DACert is valid, it provides a proof that the corresponding data is available from honest committee members.

DA BridgeSystem that verifies that data has been made available. It takes the form of a smart contract verifying a consensus or, if the data is verified directly by either downloading the full data or sampling, of an enshrined bridge. Architecture

Anytrust bridge architecture

The DA commitments are posted to the destination chain through the sequencer inbox, using the inbox as a DA bridge. The DA commitment consists of Data Availability Certificate (DACert), including a hash of the data block, an expiration time, and a proof that the required threshold of Committee members have signed off on the data. The sequencer distributes the data and collects signatures from Committee members offchain. Only the DACert is posted by the sequencer to the destination chain inbox (the DA bridge), achieving destination chain transaction ordering finalityStrongest confirmation rule that can be given on the ordering of transactions. On Ethereum, a transaction is finalized when the corresponding epoch becomes final, which currently takes around 15 mins from transaction inclusion. A rollup transaction can be said to be final when the corresponding data is published to L1 and its ordering cannot be reverted. If outputs, i.e. state diffs are published, then also a proof proving their correctness must be verified to consider the transaction final. in a single onchain transaction.

Funds can be lost if a malicious committee attests to an invalid data availability certificate.
Funds can be lost if the bridge contract or its dependencies receive a malicious code upgrade. There is no delay on code upgrades.

Inside AnyTrust - Arbitrum Docs

State validation

Updates to the system state can be proposed and challenged by a set of whitelisted validatorsIn the context of L2s, a Validator is an actor that validates the correctness of state transitions. For optimistic rollups this corresponds to challengers, and for ZK rollups this corresponds to the onchain verifier. If a state rootA cryptographic hash succinctly representing a state using a Merkle tree. passes the challenge periodIn optimistic rollups, the window of time wherein network participants can assert that some fraud was included in a prior block. Most optimistic rollups currently specify a challenge window of 7 days. By extending the period, there is more time for participants to guard against fraud (invalid state transitions), but also more time until withdrawals gets enabled., it is optimistically considered correct and made actionable for withdrawals.

State root proposals

ValidatorsIn the context of L2s, a Validator is an actor that validates the correctness of state transitions. For optimistic rollups this corresponds to challengers, and for ZK rollups this corresponds to the onchain verifier propose state rootsA cryptographic hash succinctly representing a state using a Merkle tree. as children of a previous state root. A state root can have multiple conflicting children. State roots are referred to as “assertions” within the contracts. Each chain of assertions only requires one stake, and validators staked on assertions with a child are considered inactive and can either move their stake to a new nodeA software client that participates in the network. or withdraw it. The function used to propose a new assertion is the stakeOnNewAssertion function. The stake is currently set to 0.1 ETH, and it can be slashed if the proposal is proven incorrect via a fraud proofAlso referred to as a fault proof, it is the construction of an assertion that fraud was perpetrated on an optimistic rollup. More concretely, that an invalid state transition took place according to the protocol rules. The submitter of a fraud proof would expect a reward from the optimistic rollup protocol for helping maintain the integrity of the system.. The protocol allows such funds to be trustlessly pooled together if necessary. New nodes cannot be created faster than the minimum assertion period, currently set to 15m. An assertion without “rivals” can be confirmed after the challenge periodIn optimistic rollups, the window of time wherein network participants can assert that some fraud was included in a prior block. Most optimistic rollups currently specify a challenge window of 7 days. By extending the period, there is more time for participants to guard against fraud (invalid state transitions), but also more time until withdrawals gets enabled. has passed, currently set to 30m. If a rival is present, then it is checked that the assertion is the winner in the challenge protocol.

Funds can be stolen if no whitelisted challenger disputes an invalid state root before the challenge window expires (CRITICAL).

BoLD paper

Challenges

A challenge can be started between two siblings, i.e. two different state rootsA cryptographic hash succinctly representing a state using a Merkle tree. that share the same parent, by calling the createLayerZeroEdge function in the ChallengeManager contract. Edges represent assertions, or bisected assertions, within the challenge protocol. Challenges are played via a bisection game, where asserters and challengers play together to find the first instruction of disagreement. Such instruction is then executed onchain in the WASM OneStepProver contract to determine the winner. An edge can only be bisected when rivaled. The bisection process requires no new stake as their validity is checked against a parent “history root” that contains all intermediate states. An edge can also be confirmed if itself or its descendants spend enough time being unrivaled. Such time is set to 1d. If both actors play as slow as possible, the maximum time to confirm an edge is double such value, i.e. 2d. Due to the complexities of maintaining the history root, the challenge protocol is divided into 3 levels, where the lowest level represents assertions over blocksAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over., the highest level represents assertions over single WASM instructions, and intermediate levels represent assertions over chunks of WASM instructions. When moving between levels, a new stake is required. Level 0 (block level) requires a stake of 0.0 ETH, level 1 requires a stake of 1.0 ETH, level 2 requires a stake of 1.0 ETH. The ratio between such stakes can be exploited to perform resource exhaustion attacks.

Funds can be stolen if an attacker successfully performs a resource exhaustion attack.

Fraud Proof Wars: Arbitrum BoLD

Program Hashes

Name	Hash	Repository	Verification	Used in

	0xdb69...b69a	Github		Projects used in Search for projects used in

Upgrades & Governance

Past upgrades

The metrics include upgrades on the currently used proxy contracts. Historical proxy contracts and changes of such are not included.

Count of upgrades

Last upgrade

1y 2mo ago

Avg upgrade interval

Updates

2026 May 05, 15:18 UTC

8changes

Operational role rotation across muster's Arbitrum-Orbit infra: - UpgradeExecutor ( arb1:0x10083F68... ) — EXECUTOR ROLE member 0: 0xc47a4C5F → 0x52D5E794 . - RollupProxy ( arb1:0xE383D432... ) — validator 0: 0x26C9cC56 → 0xD8099Ee0 . - SequencerInbox ( arb1:0xfb27e42E... ) — batchPosterManager + batchPoster 0: 0x922bc2d9 → 0xBF199CEf . DAC keyset BLS signature 0 also rotated (single signer key change).

Operational role rotation across muster’s Arbitrum-Orbit infra:

UpgradeExecutor (arb1:0x10083F68...) — EXECUTOR_ROLE member 0: 0xc47a4C5F → 0x52D5E794.
RollupProxy (arb1:0xE383D432...) — validator 0: 0x26C9cC56 → 0xD8099Ee0.
SequencerInbox (arb1:0xfb27e42E...) — batchPosterManager + batchPoster 0: 0x922bc2d9 → 0xBF199CEf. DAC keyset BLS signature 0 also rotated (single signer key change).

	contract UpgradeExecutor (arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36) {
	+++ description: Central contract defining the access control permissions for upgrading the system contract implementations.
	values.accessControl.EXECUTOR_ROLE.members.0:
-	"arb1:0xc47a4C5F37eD1b78128A913f68f1711ea097aE24"
+	"arb1:0x52D5E794B5a4C77Af1197EEB21ea67BEa51a238E"
	values.executors.0:
-	"arb1:0xc47a4C5F37eD1b78128A913f68f1711ea097aE24"
+	"arb1:0x52D5E794B5a4C77Af1197EEB21ea67BEa51a238E"
	}

	contract RollupProxy (arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864) {
	+++ description: 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 assertions (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both called Validators).
	values.getValidators.0:
-	"arb1:0x26C9cC5681Dc8CfA7d0CD2F52769479b54612298"
+	"arb1:0xD8099Ee073d6C023DB71efBdEB4da495f0F86844"
	}

	contract SequencerInbox (arb1:0xfb27e42E964F3364630F76D62EB295ae792BD4FA) {
	+++ description: A sequencer (registered in this contract) can submit transaction batches or commitments here.
	values.batchPosterManager:
-	"arb1:0x922bc2d9dd1c4fd0a08460DD8d3E29BfD5b99117"
+	"arb1:0xBF199CEfC1B193E4D2ec0A4d7Fb545B3a62E642A"
	values.batchPosters.0:
-	"arb1:0x922bc2d9dd1c4fd0a08460DD8d3E29BfD5b99117"
+	"arb1:0xBF199CEfC1B193E4D2ec0A4d7Fb545B3a62E642A"
	values.dacKeyset.blsSignatures.0:
-	"YAvPkaef4hf3zNeyzlRuxt0SkWz8qbJuOHEi9I8eMxUrQ7mhMmz7wi7BgpHpsPB9tBEOz/mKpGHi1aQeHcxG0QWODhT8oWHlcUvMvgpO2dhXSK6cRjDlOZy4mBXrjMJVBBOgjAkpi4UetNc2w6tyNcOa9lRekf8obnO+HHUjxiczyon2S5KCxkvtDbsEZZHeiweLET02229SZ0KZ2WksOgXQX48WeA3C4lU93vqCQQKtK9G+PEqi8ZzYfdeIi7LRUQFwcK5OoazKObLJprc1b5WkE8q9k/hiAXvhNTXJB92LSevLu/QXGYwarYzjlWkKiQBsjoKmITWIclydZCQl7dP9ooCHB3pafue9Ude9ZoXsolpU8J8Hs+aUSwqJ7uhPYg=="
+	"YBYaUY7AvF5PtkUaFCaeQM9zo/r6sZe1gP+22XnliFgSZLiBS6GCXtaAnZz50bCZgQyCkrmg7MCk67L7f968JMwB3OFrJsBBt/mo3puJB6eao3uLyuneuMNF1TF9qFJhbwG1FbrM2gNxf+KkxAnasWdhjAc2rtPNP2sEVjeHw2+ceWop+h0eEB6AkbQLKOCFuQ2zLkjsMunrqzBkdXCGkubQhqOMNll62dshemSYNaSrz70YpS81f8tzQc3W8GxbChgj44gcHk0xHp7QLxAXhQuGTAPkA/2ph3IbnUc6sElLbG5nFRPXEi9ctZ3kwzjt3wW6L/oH2rkxMLOkRg2aZAsyondNLlzOSB3nzL0MdCQRsIbIEtd7YOZohg8aX0EK7A=="
	values.keySetUpdates:
-	2
+	3
	values.setIsBatchPosterCount:
-	3
+	5
	}

2026 March 25, 10:08 UTC

1change

Challenge period (confirmPeriodBlocks) drastically reduced from 7200 to 150 L1 blocks (from ~24 hours to ~30 minutes).

	contract RollupProxy (arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864) {
	+++ description: 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 assertions (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both called Validators).
	+++ description: Challenge period. (Number of ETHEREUM blocks until a node is confirmed, even for L3s).
	values.confirmPeriodBlocks:
-	7200
+	150
	}

2026 March 05, 15:15 UTC

5changes

EXECUTOR ROLE on the UpgradeExecutor changed from 0xCa9c... to 0xc47a... . This EOA controls all upgrade permissions for the system.

EXECUTOR_ROLE on the UpgradeExecutor changed from 0xCa9c... to 0xc47a.... This EOA controls all upgrade permissions for the system.

	contract UpgradeExecutor (arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36) {
	+++ description: Central contract defining the access control permissions for upgrading the system contract implementations.
	values.accessControl.EXECUTOR_ROLE.members.0:
-	"arb1:0xCa9c24bf165D375A62E62b9fb8F138E19A957Aa9"
+	"arb1:0xc47a4C5F37eD1b78128A913f68f1711ea097aE24"
	values.executors.0:
-	"arb1:0xCa9c24bf165D375A62E62b9fb8F138E19A957Aa9"
+	"arb1:0xc47a4C5F37eD1b78128A913f68f1711ea097aE24"
	}

	EOA (arb1:0xCa9c24bf165D375A62E62b9fb8F138E19A957Aa9) {
	+++ description: None
	receivedPermissions:
-	[{"permission":"interact","from":"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864","description":"Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability and DACs, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes.","role":".owner","via":[{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0x18BB8310E3a3DF4EFcCb6B3E9AeCB8bE6d4af07f","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0x37D07D97673c79afe3b92548175Af47488E28694","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0x8987777757a91Ed09912D7A5B8430bbAC2cf153C","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0xB0EC3C1368AF7d9C2CAE6B7f8E022Cc14d59D2b1","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0xD17550876106645988051ffDd31dFc3cDaA29F9c","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864","role":"admin","via":[{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]},{"permission":"upgrade","from":"arb1:0xfb27e42E964F3364630F76D62EB295ae792BD4FA","role":"admin","via":[{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"},{"address":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36"}]}]
	controlsMajorityOfUpgradePermissions:
-	true
	directlyReceivedPermissions:
-	[{"permission":"act","from":"arb1:0x10083F68A4aEC72c567661616bd6036D3a6d1B36","role":".executors"}]
	}

2025 July 24, 07:59 UTC

High severity

65changes

Upgrade to permissioned BoLD with a single validator on standard contracts (except SequencerInbox, see below). SequencerInbox: add feeTokenPricer role who can set the conversion rate from arb gas to L3 gas token, which is irrelevant for muster as it uses ETH ([diff to arbitrum one]](https://disco.l2beat.com/diff/eth:0x98a58ADAb0f8A66A1BF4544d804bc0475dff32c7/arb1:0xfEB2537afD8519d16d0CcEa741A70f97f3D4288B))

Upgrade to permissioned BoLD with a single validator on standard contracts (except SequencerInbox, see below).

SequencerInbox: add feeTokenPricer role who can set the conversion rate from arb gas to L3 gas token, which is irrelevant for muster as it uses ETH ([diff to arbitrum one]](https://disco.l2beat.com/diff/eth:0x98a58ADAb0f8A66A1BF4544d804bc0475dff32c7/arb1:0xfEB2537afD8519d16d0CcEa741A70f97f3D4288B))

	contract UpgradeExecutor (0x10083F68A4aEC72c567661616bd6036D3a6d1B36) {
	+++ description: Central contract defining the access control permissions for upgrading the system contract implementations.
	directlyReceivedPermissions.1.description:
-	"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."
+	"Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability and DACs, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes."
	directlyReceivedPermissions.1.from:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	directlyReceivedPermissions.2.from:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	}

	contract Inbox (0x18BB8310E3a3DF4EFcCb6B3E9AeCB8bE6d4af07f) {
	+++ description: Facilitates sending L1 to L2 messages like depositing ETH, but does not escrow funds.
	sourceHashes.1:
-	"0x84cd273689e720a0b7c657b57d9fb127684f3abb87fc4b337a2f0decd9464120"
+	"0x421aa98d340c2ad3e475ce29bb1e72660c213f0997591e567c0fd3d3ae2365a8"
	values.$implementation:
-	"arb1:0x6C6cf18f13C3e9b969e3acE6b8F21DfF95d4D447"
+	"arb1:0xDD262dfDf2FCe29696f54eC5bB82C6994Ec2F639"
	values.$pastUpgrades.2:
+	["2025-07-17T02:43:49.000Z","0x3f73498578e6ec5c6869f292790ee4500dabf3b6ae1f6a60dd84f297dc7a5886",["arb1:0xDD262dfDf2FCe29696f54eC5bB82C6994Ec2F639"]]
	values.$upgradeCount:
-	2
+	3
	implementationNames.arb1:0x6C6cf18f13C3e9b969e3acE6b8F21DfF95d4D447:
-	"Inbox"
	implementationNames.arb1:0xDD262dfDf2FCe29696f54eC5bB82C6994Ec2F639:
+	"Inbox"
	}

	EOA (0x26C9cC5681Dc8CfA7d0CD2F52769479b54612298) {
	+++ description: None
	receivedPermissions.0.role:
-	".validators"
+	".getValidators"
	receivedPermissions.0.from:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	}

-	Status: DELETED
	contract OneStepProverHostIo (0x33c1514Bf90e202d242C299b37C60f908aa206D4)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

	contract ProxyAdmin (0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4) {
	+++ description: None
	directlyReceivedPermissions.2:
+	{"permission":"upgrade","from":"arb1:0x37D07D97673c79afe3b92548175Af47488E28694","role":"admin"}
	directlyReceivedPermissions.5:
-	{"permission":"upgrade","from":"arb1:0xE8c7770db364e57b2A4f5344d51b7f490aE9163A","role":"admin"}
	}

-	Status: DELETED
	contract OneStepProver0 (0x54E0923782b701044444De5d8c3A45aC890b0881)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

-	Status: DELETED
	contract ValidatorUtils (0x6c21303F5986180B1394d2C89f3e883890E2867b)
	+++ description: This contract implements view only utilities for validators.

-	Status: DELETED
	contract RollupProxy (0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1)
	+++ description: 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).

	contract RollupEventInbox (0x8987777757a91Ed09912D7A5B8430bbAC2cf153C) {
	+++ description: Helper contract sending configuration data over the bridge during the systems initialization.
	sourceHashes.1:
-	"0xcd37abd5bdcc8c37cbf37dcfa4889d5b238388344d913b3a48914f659e0d627b"
+	"0x6ce471861570d55dc6e9a09337d990c13efb0c7abb47f36a5de48a9a7086f6e8"
	values.$implementation:
-	"arb1:0xF40C24bA346aA459ED28e196D4A46Cf17174bD6C"
+	"arb1:0xf4d69939895E5f1d1ddCa96E5f93A878c80368c3"
	values.$pastUpgrades.1:
+	["2025-07-17T02:43:49.000Z","0x3f73498578e6ec5c6869f292790ee4500dabf3b6ae1f6a60dd84f297dc7a5886",["arb1:0xf4d69939895E5f1d1ddCa96E5f93A878c80368c3"]]
	values.$upgradeCount:
-	1
+	2
	values.rollup:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	implementationNames.arb1:0xF40C24bA346aA459ED28e196D4A46Cf17174bD6C:
-	"RollupEventInbox"
	implementationNames.arb1:0xf4d69939895E5f1d1ddCa96E5f93A878c80368c3:
+	"RollupEventInbox"
	}

	contract Bridge (0xB0EC3C1368AF7d9C2CAE6B7f8E022Cc14d59D2b1) {
	+++ description: 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.
	sourceHashes.1:
-	"0xb920455f1e366c7a89719abdd8d8174e4e7d353f2d4b7dea11b0571bf9526eae"
+	"0xbce819ea96dfba398ca731b4457e9b9a01621df028c459eb74b15b6a687130b1"
	values.$implementation:
-	"arb1:0xB23214f241bdEb275f7dCBfbb1EA79349101d4B0"
+	"arb1:0x81F6f682cA9bB29D759ce12d7067E1c6EF533096"
	values.$pastUpgrades.1:
+	["2025-07-17T02:43:49.000Z","0x3f73498578e6ec5c6869f292790ee4500dabf3b6ae1f6a60dd84f297dc7a5886",["arb1:0x81F6f682cA9bB29D759ce12d7067E1c6EF533096"]]
	values.$upgradeCount:
-	1
+	2
	values.rollup:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	implementationNames.arb1:0xB23214f241bdEb275f7dCBfbb1EA79349101d4B0:
-	"Bridge"
	implementationNames.arb1:0x81F6f682cA9bB29D759ce12d7067E1c6EF533096:
+	"Bridge"
	}

	EOA (0xCa9c24bf165D375A62E62b9fb8F138E19A957Aa9) {
	+++ description: None
	receivedPermissions.0.description:
-	"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."
+	"Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability and DACs, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes."
	receivedPermissions.0.from:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	receivedPermissions.3.via.0:
+	{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"}
	receivedPermissions.3.from:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0x37D07D97673c79afe3b92548175Af47488E28694"
	receivedPermissions.7.via.0:
-	{"address":"arb1:0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4"}
	receivedPermissions.7.from:
-	"arb1:0xE8c7770db364e57b2A4f5344d51b7f490aE9163A"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	}

	contract Outbox (0xD17550876106645988051ffDd31dFc3cDaA29F9c) {
	+++ description: Facilitates L2 to L1 contract calls: Messages initiated from L2 (for example withdrawal messages) eventually resolve in execution on L1.
	sourceHashes.1:
-	"0x28eec040eca7563195b19e22e11429d0f977820bfb60ac52e567ffde3c92cf77"
+	"0x9e054d18af00f58f7fa36e7a0fd5b04b9dacfb8c411d84c3591e57aa72faff9d"
	values.$implementation:
-	"arb1:0x13BE515E44Eefaf3eBEFAD684F1FBB574Ac0A494"
+	"arb1:0x4ca08847418DE7860a6da0De2e5536F1Cd78458A"
	values.$pastUpgrades.1:
+	["2025-07-17T02:43:49.000Z","0x3f73498578e6ec5c6869f292790ee4500dabf3b6ae1f6a60dd84f297dc7a5886",["arb1:0x4ca08847418DE7860a6da0De2e5536F1Cd78458A"]]
	values.$upgradeCount:
-	1
+	2
	values.rollup:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	implementationNames.arb1:0x13BE515E44Eefaf3eBEFAD684F1FBB574Ac0A494:
-	"Outbox"
	implementationNames.arb1:0x4ca08847418DE7860a6da0De2e5536F1Cd78458A:
+	"Outbox"
	}

-	Status: DELETED
	contract OneStepProofEntry (0xD89d54007079071cBA859127318b9F34eeB78049)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

-	Status: DELETED
	contract OneStepProverMath (0xE58a2dEb5718F9aAF2C1DdD0E366ED076D204cc4)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

-	Status: DELETED
	contract ChallengeManager (0xE8c7770db364e57b2A4f5344d51b7f490aE9163A)
	+++ description: Contract that allows challenging state roots. Can be called through the RollupProxy by Validators or the UpgradeExecutor.

-	Status: DELETED
	contract OneStepProverMemory (0xf8E5e5562c2c12d8690786f5C9FA65F20F6bD881)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

	contract SequencerInbox (0xfb27e42E964F3364630F76D62EB295ae792BD4FA) {
	+++ description: A sequencer (registered in this contract) can submit transaction batches or commitments here.
	sourceHashes.1:
-	"0x6bb86ac4bd0d31e049f543fcf0a8f94c952252222f115246ef9d5b8104d803cc"
+	"0xb57f3e67e08492b235337cda4f3ea0117e3e043cceaf8e9a7a51b57611ba99de"
	values.$implementation:
-	"arb1:0x066a4D939302470Bd83F1868A1Ae2485Fe75ccF2"
+	"arb1:0xfEB2537afD8519d16d0CcEa741A70f97f3D4288B"
	values.$pastUpgrades.3:
+	["2025-07-17T02:43:49.000Z","0x3f73498578e6ec5c6869f292790ee4500dabf3b6ae1f6a60dd84f297dc7a5886",["arb1:0xfEB2537afD8519d16d0CcEa741A70f97f3D4288B"]]
	values.$upgradeCount:
-	3
+	4
	values.maxTimeVariation.delayBlocks:
-	5760
+	7200
	values.rollup:
-	"arb1:0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1"
+	"arb1:0xE383D432F039f4377CC9AA003FfaE4c814936864"
	values.feeTokenPricer:
+	"arb1:0x0000000000000000000000000000000000000000"
	values.isDelayBufferable:
+	true
	implementationNames.arb1:0x066a4D939302470Bd83F1868A1Ae2485Fe75ccF2:
-	"SequencerInbox"
	implementationNames.arb1:0xfEB2537afD8519d16d0CcEa741A70f97f3D4288B:
+	"SequencerInbox"
	}

+	Status: CREATED
	contract OneStepProverHostIo (0x18Cc27B3a95a6FdEf9EAA391eff28F48F42fFe3F)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract EdgeChallengeManager (0x37D07D97673c79afe3b92548175Af47488E28694)
	+++ description: Contract that implements the main challenge protocol logic of the fraud proof system.

+	Status: CREATED
	contract OneStepProverMemory (0x583F8BA007580c83EFB4B02C66694096cD5c56d1)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract OneStepProofEntry (0x61006c8566fac9a3315F646dA4624C00BbCF15E4)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract OneStepProver0 (0x78B101eC9736c4Ab06b0833f01Fd4c011f7CA612)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract OneStepProverMath (0xB08Ca18499389ABfDF7b14b09BD2Bd4d56D7fbbb)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract RollupProxy (0xE383D432F039f4377CC9AA003FfaE4c814936864)
	+++ description: 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 assertions (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both called Validators).

2025 July 14, 12:44 UTC

15changes

Discovery rerun on the same block number with only config-related changes.

New and verified contracts

+	Status: CREATED
	contract UpgradeExecutor (0x10083F68A4aEC72c567661616bd6036D3a6d1B36)
	+++ description: Central contract defining the access control permissions for upgrading the system contract implementations.

+	Status: CREATED
	contract Inbox (0x18BB8310E3a3DF4EFcCb6B3E9AeCB8bE6d4af07f)
	+++ description: Facilitates sending L1 to L2 messages like depositing ETH, but does not escrow funds.

+	Status: CREATED
	contract OneStepProverHostIo (0x33c1514Bf90e202d242C299b37C60f908aa206D4)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract ProxyAdmin (0x37119EAcFBc1c83DDAf80F6705b6B19630C101C4)
	+++ description: None

+	Status: CREATED
	contract OneStepProver0 (0x54E0923782b701044444De5d8c3A45aC890b0881)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract ValidatorUtils (0x6c21303F5986180B1394d2C89f3e883890E2867b)
	+++ description: This contract implements view only utilities for validators.

+	Status: CREATED
	contract RollupProxy (0x73CA76d9B04661604fF950fB8DBc9f18F1B853f1)
	+++ description: 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).

+	Status: CREATED
	contract RollupEventInbox (0x8987777757a91Ed09912D7A5B8430bbAC2cf153C)
	+++ description: Helper contract sending configuration data over the bridge during the systems initialization.

+	Status: CREATED
	contract Bridge (0xB0EC3C1368AF7d9C2CAE6B7f8E022Cc14d59D2b1)
	+++ description: 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.

+	Status: CREATED
	contract Outbox (0xD17550876106645988051ffDd31dFc3cDaA29F9c)
	+++ description: Facilitates L2 to L1 contract calls: Messages initiated from L2 (for example withdrawal messages) eventually resolve in execution on L1.

+	Status: CREATED
	contract OneStepProofEntry (0xD89d54007079071cBA859127318b9F34eeB78049)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract OneStepProverMath (0xE58a2dEb5718F9aAF2C1DdD0E366ED076D204cc4)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract ChallengeManager (0xE8c7770db364e57b2A4f5344d51b7f490aE9163A)
	+++ description: Contract that allows challenging state roots. Can be called through the RollupProxy by Validators or the UpgradeExecutor.

+	Status: CREATED
	contract OneStepProverMemory (0xf8E5e5562c2c12d8690786f5C9FA65F20F6bD881)
	+++ description: One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

+	Status: CREATED
	contract SequencerInbox (0xfb27e42E964F3364630F76D62EB295ae792BD4FA)
	+++ description: A sequencer (registered in this contract) can submit transaction batches or commitments here.

Operator

The section considers only the L3 properties. For more details please refer to

Arbitrum One

The system has a centralized sequencer

While forcing transaction is open to anyone the system employs a privileged sequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. 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.

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 SequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. 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.

Sequencing

Buffered forced transactions

To force transactions from the host chain, users must first enqueue “delayed” messages in the “delayed” inbox of the BridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge. contract. Only authorized Inboxes are allowed to enqueue delayed messages, and the so-called Inbox contract is the one used as the entry point by calling the sendMessage or sendMessageFromOrigin functions. If the centralized sequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. doesn’t process the request within some time bound, users can call the forceInclusion function on the SequencerInbox contract to include the message in the canonical chain. The time bound is defined to be the minimum between 1d and the time left in the delay buffer. The delay buffer gets replenished over time and gets consumed every time the sequencer doesn’t timely process a message. Only messages processed with a delay greater than 1634y 3mo consume the buffer. The buffer is capped at 1634y 3mo. The replenish rate is currently set at 1m every 20m. Even if the buffer is fully consumed, messages are still allowed to be delayed up to 1634y 3mo.

Sequencer and censorship resistance - Arbitrum documentation

Withdrawals

The section considers only the L3 properties. For more details please refer to

Arbitrum One

Regular messaging

The user initiates L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups.->L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. messages by submitting a regular transaction on this chain. When the blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over. containing that transaction is settled, the message becomes available for processing on L1. The process of block finalization usually takes several days to complete.

Autonomous exit

Users can (eventually) exit the system by pushing the transaction on L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. and providing the corresponding state rootA cryptographic hash succinctly representing a state using a Merkle tree.. 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.

Inside Arbitrum Nitro

Permissions

A dashboard to explore contracts and permissions

Go to Disco

Explore in Disco

Arbitrum One

Actors:

EOA 10x52D5…238E

Can upgrade with no delay
- UpgradeExecutor UpgradeExecutor → ProxyAdmin
- Inbox UpgradeExecutor → ProxyAdmin
- EdgeChallengeManager UpgradeExecutor → ProxyAdmin
- RollupEventInbox UpgradeExecutor → ProxyAdmin
- BridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge. UpgradeExecutor → ProxyAdmin
- Outbox UpgradeExecutor → ProxyAdmin
- RollupProxy UpgradeExecutor
- SequencerInbox UpgradeExecutor → ProxyAdmin
Can interact with RollupProxy
- Pause and unpause and set important roles and parameters in the system contracts: Can delegate SequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. management to a BatchPosterManager address, manage data availabilityThe property of a rollup's data being reachable by any node retrieving the data that were rolled up and executed to reach the proposed state. Data availability (DA), specifically decoupling it from the rollup nodes themselves, is one of the preeminent factors which allows a rollup to scale securely. A rollup is faced with a decision of what to use as a DA layer to guarantee that any node can retrieve this data--permissionlessly under any circumstance. For this reason, using Ethereum for DA currently provides the strongest security guarantees. If data is stored somewhere other than a permissionless L1, then the project is not a rollup, but rather a validium or an optimium., DACs and the fastConfirmer role, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes UpgradeExecutor

EOA 20xBF19…642A

Can interact with SequencerInbox
- Add/remove batchPosters (Sequencers)
- Can submit transaction batches or commitments to the SequencerInbox contract on the host chain

EOA 30xD809…6844

Can interact with RollupProxy
- Can propose new state rootsA cryptographic hash succinctly representing a state using a Merkle tree. (called nodes) and challenge state roots on the host chain

Smart contracts

A dashboard to explore contracts and permissions

Go to Disco

Explore in Disco

A diagram of the smart contract architecture

Arbitrum One

EdgeChallengeManager0x37D0…8694 Implementation (Upgradable)Admin

Contract that implements the main challenge protocol logic of the fraud proof systemThe infrastructure that allows projects to verify their state transitions. It is composed by onchain verifiers and offchain provers. The main two flavors are optimistic and ZK proof systems, but they can be combined in a hybrid model. In general though, if a system is able to accept state roots optimistically, even if it has a ZK component, it is considered an optimistic proof system..

Roles:
- admin: ProxyAdmin; ultimately EOA 1

Can be upgraded by:

EOA 1 with no delay

Implementation used in:

Bridge

Escrow

0xB0EC…D2b1 Implementation (Upgradable)Admin

Escrow contract for the project’s gasA virtual fuel used to execute smart contracts on a rollup. The EVM (or other VM within the rollup) uses an accounting mechanism to correspond the consumption of gas to the consumption of computing resources, and to limit the consumption of computing resources. token (can be different from ETH). Keeps a list of allowed Inboxes and Outboxes for canonical bridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge. messaging.

Roles:
- admin: ProxyAdmin; ultimately EOA 1

The following tokens are included in the value secured calculation:

Can be upgraded by:

EOA 1 with no delay

RollupProxy0xE383…6864 Implementation #1 (Upgradable)Implementation #2 (Upgradable)Admin

Central contract for the project’s configuration like its execution logic hashA fixed-length fingerprint of variable-size input, produced by a hash function. (wasmModuleRoot) and addresses of the other system contracts. Entry point for Proposers creating new assertions (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both called ValidatorsIn the context of L2s, a Validator is an actor that validates the correctness of state transitions. For optimistic rollups this corresponds to challengers, and for ZK rollups this corresponds to the onchain verifier).

Roles:
- admin: UpgradeExecutor; ultimately EOA 1
- getValidators: EOA 3
- owner: UpgradeExecutor; ultimately EOA 1

Can be upgraded by:

EOA 1 with no delay

Implementation used in:

SequencerInbox0xfb27…D4FA Implementation (Upgradable)Admin

A sequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. (registered in this contract) can submit transaction batches or commitments here.

Roles:
- admin: ProxyAdmin; ultimately EOA 1
- batchPosterManager: EOA 2
- batchPosters: EOA 2

Can be upgraded by:

EOA 1 with no delay

UpgradeExecutor0x1008…1B36 Implementation (Upgradable)Admin

Central contract defining the access control permissions for upgrading the system contract implementations.

Roles:
- admin: ProxyAdmin; ultimately EOA 1
- executors: EOA 1

Can be upgraded by:

EOA 1 with no delay

Implementation used in:

Inbox0x18BB…f07f Implementation (Upgradable)Admin

Facilitates sending L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. to L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups. messages like depositing ETH, but does not escrow funds.

Roles:
- admin: ProxyAdmin; ultimately EOA 1

Can be upgraded by:

EOA 1 with no delay

Outbox0xD175…9F9c Implementation (Upgradable)Admin

Facilitates L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups. to L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. contract calls: Messages initiated from L2 (for example withdrawal messages) eventually resolve in execution on L1.

Roles:
- admin: ProxyAdmin; ultimately EOA 1

Can be upgraded by:

EOA 1 with no delay

OneStepProverHostIo0x18Cc…Fe3F

One of the modular contracts used for the last step of a fraud proofAlso referred to as a fault proof, it is the construction of an assertion that fraud was perpetrated on an optimistic rollup. More concretely, that an invalid state transition took place according to the protocol rules. The submitter of a fraud proof would expect a reward from the optimistic rollup protocol for helping maintain the integrity of the system., which is simulated inside a WASM virtual machine.

Implementation used in:

ProxyAdmin0x3711…01C4

Roles:
- owner: UpgradeExecutor

OneStepProverMemory0x583F…56d1

Implementation used in:

OneStepProofEntry0x6100…15E4

Implementation used in:

OneStepProver00x78B1…A612

Implementation used in:

RollupEventInbox0x8987…153C Implementation (Upgradable)Admin

Helper contract sending configuration data over the bridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge. during the systems initialization.