# Blast

Markdown version of https://l2beat.com/layer2s/projects/blast

## Summary

**Warning:** There are impactful changes and part of the information might be outdated.

**Warning:** Blast is winding down. See the [announcement](https://x.com/blast/status/2106032805280891073) and withdraw your funds to Ethereum by October 26, 2026.

**Warning:** Why is the project listed in others? The proof system isn't fully functional. Consequence: projects without a proper proof system fully rely on single entities to safely update the state. A malicious proposer can finalize an invalid state, which can cause loss of funds. Learn more about the [recategorisation](https://medium.com/l2beat/framework-update-l2-projects-recategorisation-5d43b0d1fe50).

- Total Value Secured: $23.08 M (-75.1% compared to seven days ago; canonically bridged $5.69 M, natively minted $5.21 M, externally bridged $12.17 M; 76.7% with additional trust assumptions compared to the tokens involved and the Stage assigned to the project's canonical messaging bridge)
  - **Warning:** The TVS does account for rehypothecated tokens. (sentiment: bad)
  - **Warning:** The BLAST token associated with Blast accounts for 21.8% of the TVS! (sentiment: warning)
- TVS by asset: ETH & derivatives $6.04 M (26.1%), Stablecoins $11.31 M (49.0%), BTC & derivatives $33.83 K (0.14%), Other $5.69 M (24.6%)
- Associated tokens: BLAST: $5.03 M (21.8% of TVS)
- Past day UOPS: 1.72 (-36.8% compared to seven days ago)
- Gas token: ETH
- Type: Other
- Purpose: Universal
- Host chain: Ethereum
- Chain ID: 81457

### Risks

- Sequencer failure: Self sequence (12h delay; sentiment: good)
- State validation: None (7d challenge period; sentiment: bad)
- Data availability: Onchain (sentiment: good)
- Exit window: None (sentiment: bad)
- Proposer failure: Cannot withdraw (sentiment: bad)

### About

Blast is an EVM-compatible Optimistic Rollup supporting native yield. It invests funds deposited into the L1 bridge into various DeFi protocols transferring yield back to the L2.

### Links

- Website: https://blast.io/en
- Bridge: https://blast.io/en/bridge
- Docs: https://docs.blast.io/about-blast
- Explorer: https://blastscan.io, https://blastplorer.info/, https://blastexplorer.io
- Repository: https://github.com/blast-io
- Social: https://twitter.com/blast, https://discord.com/invite/blast-l2, https://discord.com/invite/blastdevelopers
- Other: https://rollup.codes/blast, https://growthepie.com/chains/blast
- Contracts explorer (Disco): https://disco.l2beat.com/ui/p/blast

### Badges

- EVM: This project uses the Ethereum Virtual Machine to run its smart contracts and supports the Solidity programming language
- Ethereum with blobs: This project is posting its data to Ethereum as blobs
- Built on OP Stack: The project is built on the OP Stack

## Value Secured

The interactive TVS charts are shown on [the HTML page](https://l2beat.com/layer2s/projects/blast#tvs).

Token by token: [TVS breakdown](https://l2beat.com/layer2s/projects/blast/tvs-breakdown).

- [TVS chart (JSON)](https://l2beat.com/api/scaling/tvs/blast)
- [TVS breakdown by token (JSON)](https://l2beat.com/api/scaling/tvs/blast/breakdown)

## Activity

The interactive activity chart is shown on [the HTML page](https://l2beat.com/layer2s/projects/blast#activity).

- [Activity chart (JSON)](https://l2beat.com/api/scaling/activity/blast)

## Onchain costs

The section shows the operating costs that L2s pay to Ethereum.

The interactive costs chart is shown on [the HTML page](https://l2beat.com/layer2s/projects/blast#onchain-costs).

### Tracked transactions

#### Batch submissions

- transfer: 2024-02-25 01:40 UTC - now; currently used; from: [0x415c8893D514F9BC5211d36eEDA4183226b84AA7](https://etherscan.io/address/0x415c8893D514F9BC5211d36eEDA4183226b84AA7); to: [0xFf00000000000000000000000000000000081457](https://etherscan.io/address/0xFf00000000000000000000000000000000081457)

#### State updates

- functionCall: 2024-02-24 22:14 UTC - now; currently used; address: [0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76); selector: 0x9aaab648; signature: `function proposeL2Output(bytes32 _outputRoot, uint256 _l2BlockNumber, bytes32 _l1Blockhash, uint256 _l1BlockNumber)`

## Data posted

This section shows how much data the project publishes to its data-availability (DA) layer over time. The project currently posts data to [Ethereum](https://l2beat.com/data-availability/projects/ethereum/ethereum).

The interactive data posted chart is shown on [the HTML page](https://l2beat.com/layer2s/projects/blast#data-posted).

### Tracked transactions

#### Blob submissions

- DA layer Ethereum: from block 19300387 to now; currently used; inbox: [0xFf00000000000000000000000000000000081457](https://etherscan.io/address/0xFf00000000000000000000000000000000081457); sequencers: [0x415c8893D514F9BC5211d36eEDA4183226b84AA7](https://etherscan.io/address/0x415c8893D514F9BC5211d36eEDA4183226b84AA7)

## Liveness

This section shows how "live" the project's operators are by displaying how frequently they submit transactions of the selected type. It also highlights anomalies - significant deviations from their typical schedule.

No ongoing anomalies detected.

The interactive liveness chart is shown on [the HTML page](https://l2beat.com/layer2s/projects/blast#liveness).

### Tracked transactions

#### Batch submissions

- transfer: 2024-02-25 01:40 UTC - now; currently used; from: [0x415c8893D514F9BC5211d36eEDA4183226b84AA7](https://etherscan.io/address/0x415c8893D514F9BC5211d36eEDA4183226b84AA7); to: [0xFf00000000000000000000000000000000081457](https://etherscan.io/address/0xFf00000000000000000000000000000000081457)

#### State updates

- functionCall: 2024-02-24 22:14 UTC - now; currently used; address: [0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76); selector: 0x9aaab648; signature: `function proposeL2Output(bytes32 _outputRoot, uint256 _l2BlockNumber, bytes32 _l1Blockhash, uint256 _l1BlockNumber)`

## Milestones & Incidents

- 2024-05-27: [Blast Mainnet starts using blobs](https://x.com/Blast_L2/status/1793686918506623032). Blast Mainnet starts publishing data to blobs.
- 2024-03-26 (incident): [Blast upgrades to censor exploiter](https://x.com/miszke_eth/status/1772946372309737970). The Munchables exploiter is prohibited from forcing transactions.
- 2024-02-29: [Blast Network Launch](https://x.com/Blast_L2/status/1763316176263008551?s=20). Blast Network is live on mainnet.

## Risk summary

**Warning:** Fraud proof system is currently under development. Users need to trust the block proposer to submit correct L1 state roots.

### Funds can be stolen if

1. a contract receives a malicious code upgrade. There is no delay on code upgrades (CRITICAL),
2. an invalid state root is submitted to the system (CRITICAL).

### Funds can be frozen if

3. there is not enough liquidity in the bridge, transactions are locked in withdrawal queue (CRITICAL).

### MEV can be extracted if

4. the operator exploits their centralized position and frontruns user transactions.

## Risk analysis

**Warning:** Fraud proof system is currently under development. Users need to trust the block proposer to submit correct L1 state roots.

### Sequencer failure

Self sequence (12h delay; sentiment: good)

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 can be up to a 12h delay on this operation.

### State validation

None (7d challenge period; sentiment: bad)

Currently the system permits invalid state roots. More details in project overview.

### Data availability

Onchain (sentiment: good)

All of the data needed for proof construction is published on Ethereum L1.

### Exit window

None (sentiment: bad)

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

### Proposer failure

Cannot withdraw (sentiment: bad)

Only the whitelisted proposers can publish state roots on L1, so in the event of failure the withdrawals are frozen.

## Stage

Blast is not even a Stage 0 project.

### Stage 0

1 issue needs fixing.

- Met: The project calls itself a rollup.
- Met: State roots are posted to Ethereum L1.
- Met: Inputs for the state transition function are posted to Ethereum L1.
- Met: A source-available node exists that can recreate the state from Ethereum L1 data. Please note that the L2BEAT team has not verified the validity of the node source code. [View code](https://github.com/blast-io/blast)
- Issue: The proof system is still under development.

### Stage 1

3 issues need fixing.

**Principle**

- Issue: Compromising ≥75% of the Security Council should be the only way (other than bugs) for a rollup to indefinitely block an L2→L1 message (e.g. a withdrawal) or push an invalid L2→L1 message (e.g. an invalid withdrawal) with a <7d exit window.

**Guidelines**

- Issue: Users' withdrawals can be censored by the permissioned operators.
- Issue: Upgrades executed by actors with more centralized control than a Security Council provide less than 7d for users to exit if the permissioned operator is down or censoring.

### Stage 2

1 issue needs fixing.

- Issue: Upgrades unrelated to onchain provable bugs provide less than 30d to exit.

[Learn more about Stages](https://l2beat.com/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

### All data required for proofs is published on chain

All the data that is used to construct the system state is published on chain in the form of cheap blobs or calldata. This ensures that it will be available for enough time.

**References**

- [Derivation: Batch submission - OP Mainnet specs](https://github.com/ethereum-optimism/specs/blob/main/specs/protocol/derivation.md#batch-submission)
- [BatchInbox - address](https://etherscan.io/address/0xFf00000000000000000000000000000000081457#code)
- [OptimismPortal.sol - source code, depositTransaction function](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code)

Learn more about the DA layer here: [Ethereum](https://l2beat.com/data-availability/projects/ethereum/ethereum)

## State derivation

### Node software

Node software can be found [here](https://github.com/blast-io/blast).

### Compression scheme

Data batches are compressed using the [zlib](https://github.com/madler/zlib) algorithm with best compression level.

### Genesis state

The genesis file can be found [here](https://github.com/blast-io/deployment/blob/master/mainnet/genesis.json).

### Data format

The format specification of Sequencer's data batches can be found [here](https://optimism.io/blog/here-s-how-you-can-reproduce-op-mainnet-s-migration-to-bedrock).

## State validation

### No state validation

OP Stack projects can use the OP fault proof system, already being deployed on some. This project though is not using fault proofs yet and is relying on the honesty of the permissioned Proposer and Challengers to ensure state correctness. The smart contract system permits invalid state roots.

**Risks**

- Funds can be stolen if an invalid state root is submitted to the system (CRITICAL).

**References**

- [L2OutputOracle.sol - source code, deleteL2Outputs function](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code)

## 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: 7
- Last upgrade: 2y 2mo ago
- Avg upgrade interval: 11mo 26d

- 2024-07-16 03:45 UTC, upgrade of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0xf9716c8e311c27decc5858f10b2a2c83ef3d8ce3958cfb242df5415a75b1e6eb](https://etherscan.io/tx/0xf9716c8e311c27decc5858f10b2a2c83ef3d8ce3958cfb242df5415a75b1e6eb), implementations: [0x1C90963D451316E3DBFdD5A30354EE56C29016EB](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code) ([diff](https://disco.l2beat.com/diff/eth:0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF/eth:0x1C90963D451316E3DBFdD5A30354EE56C29016EB))
- 2024-03-27 01:00 UTC, upgrade of [OptimismPortal](https://etherscan.io/address/0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb#code): transaction [0xb813416a1e599fbebc813b4e9a8c29e5d94d45e8da6e10e86935768caed38e98](https://etherscan.io/tx/0xb813416a1e599fbebc813b4e9a8c29e5d94d45e8da6e10e86935768caed38e98), implementations: [0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code) ([diff](https://disco.l2beat.com/diff/eth:0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32/eth:0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391))
- 2024-02-29 09:56 UTC, upgrade of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0x4e7b5b82e00b92a5b0380e3a47801760a35f00462793f28926184e984cddc478](https://etherscan.io/tx/0x4e7b5b82e00b92a5b0380e3a47801760a35f00462793f28926184e984cddc478), implementations: [0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF](https://etherscan.io/address/0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF#code) ([diff](https://disco.l2beat.com/diff/eth:0x1c952514f0353d84d9ad35BcfB8E9Ea979289031/eth:0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF))
- 2024-02-27 01:32 UTC, upgrade of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0xcd5f72853d01d93a1fbf3d219a77c7f0243b0fd537d14737c3b0691f0897d67c](https://etherscan.io/tx/0xcd5f72853d01d93a1fbf3d219a77c7f0243b0fd537d14737c3b0691f0897d67c), implementations: [0x84efcFCE2dEe08072d5D57BF232D379b6E92A836](https://etherscan.io/address/0x84efcFCE2dEe08072d5D57BF232D379b6E92A836#code) ([diff](https://disco.l2beat.com/diff/eth:0xe7406f6d89a14aC3Fc28530479327948ea500659/eth:0x84efcFCE2dEe08072d5D57BF232D379b6E92A836))
- 2024-02-24 22:26 UTC, deployment of [OptimismPortal](https://etherscan.io/address/0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb#code): transaction [0xf82923e94578148fd33c7e506f9e5db98ca060c911b41c5b6697d167738dd6a0](https://etherscan.io/tx/0xf82923e94578148fd33c7e506f9e5db98ca060c911b41c5b6697d167738dd6a0), implementations: [0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32](https://etherscan.io/address/0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32#code)
- 2024-02-24 22:25 UTC, deployment of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0x6294e04e136d66468e369543e2789863e2f036ab8e80d473d6808e414c3e233a](https://etherscan.io/tx/0x6294e04e136d66468e369543e2789863e2f036ab8e80d473d6808e414c3e233a), implementations: [0x1c952514f0353d84d9ad35BcfB8E9Ea979289031](https://etherscan.io/address/0x1c952514f0353d84d9ad35BcfB8E9Ea979289031#code)
- 2024-02-24 22:25 UTC, upgrade of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0x718f17591631857e26554f08b52874c1826d990a5c53d8496b12c860509615ed](https://etherscan.io/tx/0x718f17591631857e26554f08b52874c1826d990a5c53d8496b12c860509615ed), implementations: [0xe7406f6d89a14aC3Fc28530479327948ea500659](https://etherscan.io/address/0xe7406f6d89a14aC3Fc28530479327948ea500659#code) ([diff](https://disco.l2beat.com/diff/eth:0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0/eth:0xe7406f6d89a14aC3Fc28530479327948ea500659))
- 2024-02-24 22:24 UTC, deployment of [OptimismMintableERC20Factory](https://etherscan.io/address/0x6B916DcCa661d23794e78509723A6f4348564847#code): transaction [0x56b371e38c6925d31d80525dc061b211c4c5070dfea14e6e34036f731443c516](https://etherscan.io/tx/0x56b371e38c6925d31d80525dc061b211c4c5070dfea14e6e34036f731443c516), implementations: [0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F](https://etherscan.io/address/0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F#code)
- 2024-02-24 22:24 UTC, deployment of [L1ERC721Bridge](https://etherscan.io/address/0xa45A0c7C47DB8C6e99b2d7C4939F7f7Cf69C8975#code): transaction [0x90946309f20c1cbbf4e4204b8f1aebb438908064a941cbd0882028dbe04dab22](https://etherscan.io/tx/0x90946309f20c1cbbf4e4204b8f1aebb438908064a941cbd0882028dbe04dab22), implementations: [0x3B01aDF2f199144233A536b08244d63e5eb691B8](https://etherscan.io/address/0x3B01aDF2f199144233A536b08244d63e5eb691B8#code)
- 2024-02-24 22:20 UTC, deployment of [SystemConfig](https://etherscan.io/address/0x5531DcfF39EC1ec727C4c5D2fc49835368F805a9#code): transaction [0xbe85666f88251637a983ac9ef301efcaa2fb56f8303b769b634404955be5dabf](https://etherscan.io/tx/0xbe85666f88251637a983ac9ef301efcaa2fb56f8303b769b634404955be5dabf), implementations: [0xA150f19B681a06E1a0B7E03934299a9bf9238cb7](https://etherscan.io/address/0xA150f19B681a06E1a0B7E03934299a9bf9238cb7#code)
- 2024-02-24 22:16 UTC, deployment of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0xb9df50a5931e96f2c6f8055055cf2943009705a369b845fbb3e0202a7b897223](https://etherscan.io/tx/0xb9df50a5931e96f2c6f8055055cf2943009705a369b845fbb3e0202a7b897223), implementations: [0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code)
- 2024-02-19 01:12 UTC, upgrade of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0x57c1c448e2afa4910ac0637260bcca28a4f0cd0b32abb001b261338962d38052](https://etherscan.io/tx/0x57c1c448e2afa4910ac0637260bcca28a4f0cd0b32abb001b261338962d38052), implementations: [0x0bD88b59D580549285f0A207Db5F06bf24a8e561](https://etherscan.io/address/0x0bD88b59D580549285f0A207Db5F06bf24a8e561#code) ([diff](https://disco.l2beat.com/diff/eth:0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774/eth:0x0bD88b59D580549285f0A207Db5F06bf24a8e561))
- 2023-12-11 19:01 UTC, upgrade of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0xb325f82fb0bd7454471789a44740a7bd3a81690a4e9c411e5c53e9412de149ca](https://etherscan.io/tx/0xb325f82fb0bd7454471789a44740a7bd3a81690a4e9c411e5c53e9412de149ca), implementations: [0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774](https://etherscan.io/address/0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774#code) ([diff](https://disco.l2beat.com/diff/eth:0xa01Def05A37850b2e13C8c839AA268845Df14276/eth:0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774))
- 2023-11-19 01:59 UTC, deployment of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0xb7f9a32a4d0d38440243d90730e7048ab1eea8c5301da80805131205a7759b4e](https://etherscan.io/tx/0xb7f9a32a4d0d38440243d90730e7048ab1eea8c5301da80805131205a7759b4e), implementations: [0xa01Def05A37850b2e13C8c839AA268845Df14276](https://etherscan.io/address/0xa01Def05A37850b2e13C8c839AA268845Df14276#code)

## Updates

Each date links the update on the HTML page, which also shows its contract diffs.

### [2026-02-26 15:06 UTC](https://l2beat.com/layer2s/projects/blast?update=1b80f245) (1 change)

BlastMultisig 1: member #5 rotated from 0x2cF48F69 to 0x7DbDFbb2. Threshold remains 3 of 5.

### [2025-07-14 12:44 UTC](https://l2beat.com/layer2s/projects/blast?update=18b336b0) (17 changes)

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

### [2024-09-02 06:44 UTC](https://l2beat.com/layer2s/projects/blast?update=d9ed2dd5) (high severity, 1 change)

USDYieldManager contract is upgraded to change the immutable constant PSM to the [new price stability module 'LITE-PSM-USDC-A'](https://vote.makerdao.com/executive/template-executive-vote-lite-psm-usdc-a-phase-2-setup-august-22-2024) by MakerDAO.

### [2024-07-16 08:31 UTC](https://l2beat.com/layer2s/projects/blast?update=f6b8f1b0) (high severity, 3 changes)

A new L2OutputOracle implementation is deployed in order to change the constant FINALIZATION_PERIOD_SECONDS (challenge period) from 12 to 7 days.

### [2024-05-28 05:57 UTC](https://l2beat.com/layer2s/projects/blast?update=2fd463b6) (3 changes)

Blast uses blobs.

### [2024-03-27 13:29 UTC](https://l2beat.com/layer2s/projects/blast?update=51df6d30) (high severity, 2 changes)

Blast is manually blacklisting three addresses from the depositTransaction() function in this implementation change of the OptimismPortal.

One of them is labeled 'Munchables exploiter' on etherscan.
(0x6E8836F050A315611208A5CD7e228701563D09c5, 0xc207Fa4b17cA710BA53F06fEFF56ca9d315915B7, 0xbf9ad762DBaE603BC8FC79DFD3Fb26f2b9740E87)

depositTransaction() in the OptimismPortal would allow a user to force an L2 transaction from L1 (e.g. a bridge transaction). Censoring it combined with censoring the L2 addresses from the Sequencer's side can effectively freeze the funds on L2.

The only other change is that a YIELD_CONTRACT_ADDRESS is introduced to a null address in constants.sol.

### [2024-03-19 09:33 UTC](https://l2beat.com/layer2s/projects/blast?update=57bac00e) (2 changes)

The insurance fee is disabled on ETH- and USDYieldManager. This fee was taken from positive yields.

### [2024-03-11 12:49 UTC](https://l2beat.com/layer2s/projects/blast?update=f1696eed) (3 changes)

Update discovery to include the multisig threshold.

### [2024-03-05 14:07 UTC](https://l2beat.com/layer2s/projects/blast?update=9f0ea2a0) (2 changes)

Added manually Yield Providers. This will have to be updated to find them automatically.

### [2024-03-04 10:56 UTC](https://l2beat.com/layer2s/projects/blast?update=1d366185) (2 changes)

Blast is using different Yield Providers and generally invests token deposits
to a bridge on L1. We should in the future discover different yield providers
but this will require discovery improvements. Right now the decision is made
to treat minted tokens on BLAST as externally bridged given fundamentally different
risk profile of these tokens.

### [2024-03-01 14:14 UTC](https://l2beat.com/layer2s/projects/blast?update=e04a70c4) (15 changes)

Mainnet launch, the config is not yet complete. Assume that the project after
this commit is in under-review state.

### [2024-02-19 09:23 UTC](https://l2beat.com/layer2s/projects/blast?update=5cd7ab32) (high severity, 6 changes)

The implementation is upgraded. See Diff below for the changes.

### [2023-12-12 16:53 UTC](https://l2beat.com/layer2s/projects/blast?update=9c0592e4) (high severity, 6 changes)

Change in the Bridge implementation. A 24h timelock is introduced on Admin Proxy updates and Bridge Transition updates. The update proposals can be created by the owner and canceled by the owner if not executed yet. Updates that do not go through the timelock will now revert.

Users can now withdraw in two cases:

- While there is an active proposal for upgrade/transition. In that case users will lose their points.
- After the contract has expired (currently set to 1 June 2024)

Other changes: The \_moveETH and \_moveUSD functions are refactored to return the assets value (previously executing the transfer), the actual transfer to the new bridge is now done within the transition function.

### [2023-12-04 15:05 UTC](https://l2beat.com/layer2s/projects/blast?update=adcb81eb) (1 change)

Change in BridgeOwner (multisig) owners.

### [2023-11-21 08:08 UTC](https://l2beat.com/layer2s/projects/blast?update=e2395db6) (2 changes)

Update discovery to include the multisig threshold.

## Operator

### The system has a centralized operator

The operator is the only entity that can propose blocks. A live and trustworthy operator is vital to the health of the system.

**Risks**

- MEV can be extracted if the operator exploits their centralized position and frontruns user transactions.

**References**

- [L2OutputOracle.sol - source code, CHALLENGER address](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code)
- [L2OutputOracle.sol - source code, PROPOSER address](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code)

### 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.

**References**

- [Sequencing Window - OP Mainnet Specs](https://github.com/ethereum-optimism/optimism/blob/51eeb76efeb32b3df3e978f311188aa29f5e3e94/specs/glossary.md#sequencing-window)
- [OptimismPortal.sol - source code, depositTransaction function](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code)

## Withdrawals

### Regular exit

The user initiates the withdrawal by submitting a regular transaction on this chain. When the block containing that transaction is settled the funds become available for withdrawal on L1. The process of block finalization takes a challenge period of 7d to complete. Once funds are added to the withdrawal queue, operator must ensure there is enough liquidity for withdrawals. If not, they need to reclaim tokens from Yield Providers.

**Risks**

- Funds can lose value if there is a hack or the yield goes negative for yield providers (CRITICAL).
- Funds can be frozen if there is not enough liquidity in the bridge, transactions are locked in withdrawal queue (CRITICAL).

**References**

- [OptimismPortal.sol - Etherscan source code, proveWithdrawalTransaction function](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code)
- [OptimismPortal.sol - Etherscan source code, finalizeWithdrawalTransaction function](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code)
- [L2OutputOracle.sol - Etherscan source code, PROPOSER check](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code)

### Forced messaging

If the user experiences censorship from the operator with regular L2->L1 messaging they can submit their messages directly on L1. The system is then obliged to service this request or halt all messages, including forced withdrawals from L1 and regular messages initiated on L2. Once the force operation is submitted and if the request is serviced, the operation follows the flow of a regular message.

**References**

- [Forced transaction from an OP Stack blockchain](https://docs.optimism.io/stack/transactions/forced-transaction)

## Other considerations

### EVM compatible smart contracts are supported

OP stack chains are pursuing the EVM Equivalence model. No changes to smart contracts are required regardless of the language they are written in, i.e. anything deployed on L1 can be deployed on L2.

**References**

- [Introducing EVM Equivalence](https://medium.com/ethereum-optimism/introducing-evm-equivalence-5c2021deb306)

## Permissions

Explore these contracts and permissions in Disco, L2BEAT's contract explorer: https://disco.l2beat.com/ui/p/blast

### Ethereum

#### Actors

##### BlastMultisig 1

Addresses: [0x4f72ee94B8ba3Be7F886565d3583A7F636c58B05](https://etherscan.io/address/0x4f72ee94B8ba3Be7F886565d3583A7F636c58B05)

A Multisig with 3/5 threshold.
- Can upgrade **with no delay**
  - OptimismPortal [via: ProxyAdmin]
  - L1BlastBridge [via: ProxyAdmin]
  - SystemConfig [via: ProxyAdmin]
  - L1CrossDomainMessenger [via: ProxyAdmin]
  - L1StandardBridge [via: ProxyAdmin]
  - OptimismMintableERC20Factory [via: ProxyAdmin]
  - L2OutputOracle [via: ProxyAdmin]
  - ETHYieldManager [via: ProxyAdmin]
  - USDYieldManager [via: ProxyAdmin]
  - L1ERC721Bridge [via: ProxyAdmin]
- Can interact with OptimismPortal
  - Allowed to pause withdrawals. In op stack systems with a proof system, the Guardian can also blacklist dispute games and set the respected game type (permissioned / permissionless)
- Can interact with SystemConfig
  - it can update the preconfer address, the batch submitter (Sequencer) address and the gas configuration of the system
- Can interact with L2OutputOracle
  - Allowed to challenge or delete state roots proposed by a Proposer
- Can interact with AddressManager
  - set and change address mappings [via: ProxyAdmin]

Participants (5): [0x6520ad883d3D76f0120443c72AD7463cab2439a4](https://etherscan.io/address/0x6520ad883d3D76f0120443c72AD7463cab2439a4), [0x480Ea8bA8De8d05A30F4f4CBedE1e28E05aE1B2C](https://etherscan.io/address/0x480Ea8bA8De8d05A30F4f4CBedE1e28E05aE1B2C), [0xf97eC9b92Efda3afe52945B4e9adE0394C9E705d](https://etherscan.io/address/0xf97eC9b92Efda3afe52945B4e9adE0394C9E705d), [0xAb5972612e8CEe66f246feaCB8D500DF3C6cfADA](https://etherscan.io/address/0xAb5972612e8CEe66f246feaCB8D500DF3C6cfADA), [0x7DbDFbb265bF26e626B44132eF4e3A3E6eEc1282](https://etherscan.io/address/0x7DbDFbb265bF26e626B44132eF4e3A3E6eEc1282)

##### BlastMultisig 2

Addresses: [0x67CA7Ca75b69711cfd48B44eC3F64E469BaF608C](https://etherscan.io/address/0x67CA7Ca75b69711cfd48B44eC3F64E469BaF608C)

A Multisig with 3/5 threshold.
- Can upgrade **with no delay**
  - LaunchBridge

Participants (5): [0x49d495DE356259458120bfd7bCB463CFb6D6c6BA](https://etherscan.io/address/0x49d495DE356259458120bfd7bCB463CFb6D6c6BA), [0xb7c719eB2649c1F03bFab68b0AAa35AD538a7cC8](https://etherscan.io/address/0xb7c719eB2649c1F03bFab68b0AAa35AD538a7cC8), [0x1f97306039530ADB4173C3786e86fab5e6b90F41](https://etherscan.io/address/0x1f97306039530ADB4173C3786e86fab5e6b90F41), [0x6a356C0EAA560f00127Adf5108FfAf503b9f1e11](https://etherscan.io/address/0x6a356C0EAA560f00127Adf5108FfAf503b9f1e11), [0x46e31F27Df5047D7Fad9b1E8DFFec635cF6efAcF](https://etherscan.io/address/0x46e31F27Df5047D7Fad9b1E8DFFec635cF6efAcF)

##### EOA 1

Addresses: [0x082b616Ec99167B2FEdee053F07db6795D4dA821](https://etherscan.io/address/0x082b616Ec99167B2FEdee053F07db6795D4dA821)

- Can interact with L2OutputOracle
  - Allowed to post new state roots of the current layer to the host chain

##### EOA 2

Addresses: [0x415c8893D514F9BC5211d36eEDA4183226b84AA7](https://etherscan.io/address/0x415c8893D514F9BC5211d36eEDA4183226b84AA7)

- Can interact with SystemConfig
  - Allowed to commit transactions from the current layer to the host chain

## Smart contracts

**Note:** Contracts presented in this section had their implementations updated since the last time our team looked at this project. The information presented may be inaccurate.

![A diagram of the smart contract architecture](https://l2beat.com/static/images/architecture/blast.07cbfd07.png)

Explore these contracts and permissions in Disco, L2BEAT's contract explorer: https://disco.l2beat.com/ui/p/blast

### Ethereum

#### OptimismPortal (escrow)

Addresses: [0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb](https://etherscan.io/address/0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb#code), [0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: 1, Last upgrade: 2y 6mo ago, Avg upgrade interval: 1y 3mo)

- 2024-03-27 01:00 UTC, upgrade of [OptimismPortal](https://etherscan.io/address/0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb#code): transaction [0xb813416a1e599fbebc813b4e9a8c29e5d94d45e8da6e10e86935768caed38e98](https://etherscan.io/tx/0xb813416a1e599fbebc813b4e9a8c29e5d94d45e8da6e10e86935768caed38e98), implementations: [0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391](https://etherscan.io/address/0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391#code) ([diff](https://disco.l2beat.com/diff/eth:0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32/eth:0xA280aEBF81c917DbD2aA1b39f979dfECEc9e4391))
- 2024-02-24 22:26 UTC, deployment of [OptimismPortal](https://etherscan.io/address/0x0Ec68c5B10F21EFFb74f2A5C61DFe6b08C0Db6Cb#code): transaction [0xf82923e94578148fd33c7e506f9e5db98ca060c911b41c5b6697d167738dd6a0](https://etherscan.io/tx/0xf82923e94578148fd33c7e506f9e5db98ca060c911b41c5b6697d167738dd6a0), implementations: [0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32](https://etherscan.io/address/0xd7bfDa9B3b014b16bada89F206607a8Ac7c6FB32#code)

The main entry point to deposit funds from host chain to this chain. It also allows to prove and finalize withdrawals.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1
  - **guardian**: BlastMultisig 1

The following tokens are included in the value secured calculation: ETH

Can be upgraded by: BlastMultisig 1 with no delay

#### SystemConfig

Addresses: [0x5531DcfF39EC1ec727C4c5D2fc49835368F805a9](https://etherscan.io/address/0x5531DcfF39EC1ec727C4c5D2fc49835368F805a9#code), [0xA150f19B681a06E1a0B7E03934299a9bf9238cb7](https://etherscan.io/address/0xA150f19B681a06E1a0B7E03934299a9bf9238cb7#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-02-24 22:20 UTC, deployment of [SystemConfig](https://etherscan.io/address/0x5531DcfF39EC1ec727C4c5D2fc49835368F805a9#code): transaction [0xbe85666f88251637a983ac9ef301efcaa2fb56f8303b769b634404955be5dabf](https://etherscan.io/tx/0xbe85666f88251637a983ac9ef301efcaa2fb56f8303b769b634404955be5dabf), implementations: [0xA150f19B681a06E1a0B7E03934299a9bf9238cb7](https://etherscan.io/address/0xA150f19B681a06E1a0B7E03934299a9bf9238cb7#code)

Contains configuration parameters such as the Sequencer address, gas limit on this chain and the unsafe block signer address.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1
  - **batcherHash**: EOA 2
  - **owner**: BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

#### L1CrossDomainMessenger

Addresses: [0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code), [0x84efcFCE2dEe08072d5D57BF232D379b6E92A836](https://etherscan.io/address/0x84efcFCE2dEe08072d5D57BF232D379b6E92A836#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: 2, Last upgrade: 2y 7mo ago, Avg upgrade interval: 10mo 18d)

- 2024-02-27 01:32 UTC, upgrade of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0xcd5f72853d01d93a1fbf3d219a77c7f0243b0fd537d14737c3b0691f0897d67c](https://etherscan.io/tx/0xcd5f72853d01d93a1fbf3d219a77c7f0243b0fd537d14737c3b0691f0897d67c), implementations: [0x84efcFCE2dEe08072d5D57BF232D379b6E92A836](https://etherscan.io/address/0x84efcFCE2dEe08072d5D57BF232D379b6E92A836#code) ([diff](https://disco.l2beat.com/diff/eth:0xe7406f6d89a14aC3Fc28530479327948ea500659/eth:0x84efcFCE2dEe08072d5D57BF232D379b6E92A836))
- 2024-02-24 22:25 UTC, upgrade of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0x718f17591631857e26554f08b52874c1826d990a5c53d8496b12c860509615ed](https://etherscan.io/tx/0x718f17591631857e26554f08b52874c1826d990a5c53d8496b12c860509615ed), implementations: [0xe7406f6d89a14aC3Fc28530479327948ea500659](https://etherscan.io/address/0xe7406f6d89a14aC3Fc28530479327948ea500659#code) ([diff](https://disco.l2beat.com/diff/eth:0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0/eth:0xe7406f6d89a14aC3Fc28530479327948ea500659))
- 2024-02-24 22:16 UTC, deployment of [L1CrossDomainMessenger](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code): transaction [0xb9df50a5931e96f2c6f8055055cf2943009705a369b845fbb3e0202a7b897223](https://etherscan.io/tx/0xb9df50a5931e96f2c6f8055055cf2943009705a369b845fbb3e0202a7b897223), implementations: [0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0](https://etherscan.io/address/0x5D4472f31Bd9385709ec61305AFc749F0fA8e9d0#code)

Sends messages from host chain to this chain, and relays messages back onto host chain. In the event that a message sent from host chain to this chain is rejected for exceeding this chain's epoch gas limit, it can be resubmitted via this contract's replay function.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

#### L1StandardBridge (escrow)

Addresses: [0x697402166Fbf2F22E970df8a6486Ef171dbfc524](https://etherscan.io/address/0x697402166Fbf2F22E970df8a6486Ef171dbfc524#code), [0xD2C23A5A280AFF9182b953579f62EDdDF1c7ff22](https://etherscan.io/address/0xD2C23A5A280AFF9182b953579f62EDdDF1c7ff22#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

The main entry point to deposit ERC20 tokens from host chain to this chain.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

All supported tokens in this escrow are included in the value secured calculation.

Can be upgraded by: BlastMultisig 1 with no delay

#### L1ERC721Bridge

Addresses: [0xa45A0c7C47DB8C6e99b2d7C4939F7f7Cf69C8975](https://etherscan.io/address/0xa45A0c7C47DB8C6e99b2d7C4939F7f7Cf69C8975#code), [0x3B01aDF2f199144233A536b08244d63e5eb691B8](https://etherscan.io/address/0x3B01aDF2f199144233A536b08244d63e5eb691B8#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-02-24 22:24 UTC, deployment of [L1ERC721Bridge](https://etherscan.io/address/0xa45A0c7C47DB8C6e99b2d7C4939F7f7Cf69C8975#code): transaction [0x90946309f20c1cbbf4e4204b8f1aebb438908064a941cbd0882028dbe04dab22](https://etherscan.io/tx/0x90946309f20c1cbbf4e4204b8f1aebb438908064a941cbd0882028dbe04dab22), implementations: [0x3B01aDF2f199144233A536b08244d63e5eb691B8](https://etherscan.io/address/0x3B01aDF2f199144233A536b08244d63e5eb691B8#code)

Used to bridge ERC-721 tokens from host chain to this chain.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

#### DSRYieldProvider

Addresses: [0x0733F618118bF420b6b604c969498ecf143681a8](https://etherscan.io/address/0x0733F618118bF420b6b604c969498ecf143681a8#code)

Yield Provider for DAI investing DAI into the MakerDAO DSR.

#### ProxyAdmin

Addresses: [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code)

- Roles:
  - **owner**: BlastMultisig 1

#### L1BlastBridge

Addresses: [0x3a05E5d33d7Ab3864D53aaEc93c8301C1Fa49115](https://etherscan.io/address/0x3a05E5d33d7Ab3864D53aaEc93c8301C1Fa49115#code), [0x7A2075519Dd9598b62075FD397aF0Dd34b14619a](https://etherscan.io/address/0x7A2075519Dd9598b62075FD397aF0Dd34b14619a#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

Custom bridge gateway for Blast that allows the Operators to reinvest L1 tokens while they are bridged to the L2.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

#### LidoYieldProvider

Addresses: [0x4316A00D31da1313617DbB04fD92F9fF8D1aF7Db](https://etherscan.io/address/0x4316A00D31da1313617DbB04fD92F9fF8D1aF7Db#code)

Yield Provider for ETH investing ETH into stETH.

#### LaunchBridge (custom escrow)

Addresses: [0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code), [0x0bD88b59D580549285f0A207Db5F06bf24a8e561](https://etherscan.io/address/0x0bD88b59D580549285f0A207Db5F06bf24a8e561#code) (Implementation (Upgradable)), [0x67CA7Ca75b69711cfd48B44eC3F64E469BaF608C](https://etherscan.io/address/0x67CA7Ca75b69711cfd48B44eC3F64E469BaF608C#code) (Admin)

**Past upgrades** (Count of upgrades: 2, Last upgrade: 2y 7mo ago, Avg upgrade interval: 11mo 21d)

- 2024-02-19 01:12 UTC, upgrade of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0x57c1c448e2afa4910ac0637260bcca28a4f0cd0b32abb001b261338962d38052](https://etherscan.io/tx/0x57c1c448e2afa4910ac0637260bcca28a4f0cd0b32abb001b261338962d38052), implementations: [0x0bD88b59D580549285f0A207Db5F06bf24a8e561](https://etherscan.io/address/0x0bD88b59D580549285f0A207Db5F06bf24a8e561#code) ([diff](https://disco.l2beat.com/diff/eth:0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774/eth:0x0bD88b59D580549285f0A207Db5F06bf24a8e561))
- 2023-12-11 19:01 UTC, upgrade of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0xb325f82fb0bd7454471789a44740a7bd3a81690a4e9c411e5c53e9412de149ca](https://etherscan.io/tx/0xb325f82fb0bd7454471789a44740a7bd3a81690a4e9c411e5c53e9412de149ca), implementations: [0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774](https://etherscan.io/address/0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774#code) ([diff](https://disco.l2beat.com/diff/eth:0xa01Def05A37850b2e13C8c839AA268845Df14276/eth:0x829e8Bf84569A0B2da7B27f975F026fDb6e0a774))
- 2023-11-19 01:59 UTC, deployment of [LaunchBridge](https://etherscan.io/address/0x5F6AE08B8AeB7078cf2F96AFb089D7c9f51DA47d#code): transaction [0xb7f9a32a4d0d38440243d90730e7048ab1eea8c5301da80805131205a7759b4e](https://etherscan.io/tx/0xb7f9a32a4d0d38440243d90730e7048ab1eea8c5301da80805131205a7759b4e), implementations: [0xa01Def05A37850b2e13C8c839AA268845Df14276](https://etherscan.io/address/0xa01Def05A37850b2e13C8c839AA268845Df14276#code)

- Roles:
  - **admin**: BlastMultisig 2

The following tokens are included in the value secured calculation: stETH

Can be upgraded by: BlastMultisig 2 with no delay

#### OptimismMintableERC20Factory

Addresses: [0x6B916DcCa661d23794e78509723A6f4348564847](https://etherscan.io/address/0x6B916DcCa661d23794e78509723A6f4348564847#code), [0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F](https://etherscan.io/address/0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-02-24 22:24 UTC, deployment of [OptimismMintableERC20Factory](https://etherscan.io/address/0x6B916DcCa661d23794e78509723A6f4348564847#code): transaction [0x56b371e38c6925d31d80525dc061b211c4c5070dfea14e6e34036f731443c516](https://etherscan.io/tx/0x56b371e38c6925d31d80525dc061b211c4c5070dfea14e6e34036f731443c516), implementations: [0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F](https://etherscan.io/address/0xBF21bc9AFaF817145B3886caDAF0860A2A0D782F#code)

A helper contract that generates OptimismMintableERC20 contracts on the network it's deployed to. OptimismMintableERC20 is a standard extension of the base ERC20 token contract designed to allow the L1StandardBridge contracts to mint and burn tokens. This makes it possible to use an OptimismMintableERC20 as this chain's representation of a token on the host chain, or vice-versa.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

#### ETHYieldManager (custom escrow)

Addresses: [0x98078db053902644191f93988341E31289E1C8FE](https://etherscan.io/address/0x98078db053902644191f93988341E31289E1C8FE#code), [0xf2F6148327B3020610FCa26E094D9A5cc4689525](https://etherscan.io/address/0xf2F6148327B3020610FCa26E094D9A5cc4689525#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

Contract managing Yield Providers for ETH.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

The following tokens are included in the value secured calculation: ETH, stETH

Can be upgraded by: BlastMultisig 1 with no delay

#### USDYieldManager

Addresses: [0xa230285d5683C74935aD14c446e137c8c8828438](https://etherscan.io/address/0xa230285d5683C74935aD14c446e137c8c8828438#code), [0xeCDdf748A60E23609c07af6CA3856744B139B911](https://etherscan.io/address/0xeCDdf748A60E23609c07af6CA3856744B139B911#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

Contract escrowing stablecoins and managing Yield Providers for stablecoins (like for example DAI).
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1

Can be upgraded by: BlastMultisig 1 with no delay

**Warning:** There are impactful changes to the following contracts, and part of the information might be outdated.

#### L2OutputOracle (impactful change)

Addresses: [0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code), [0x1C90963D451316E3DBFdD5A30354EE56C29016EB](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code) (Implementation (Upgradable)), [0x364289230b8cc7d9120eF962AF37ebCFe23cE883](https://etherscan.io/address/0x364289230b8cc7d9120eF962AF37ebCFe23cE883#code) (Admin)

**Past upgrades** (Count of upgrades: 2, Last upgrade: 2y 2mo ago, Avg upgrade interval: 10mo 18d)

- 2024-07-16 03:45 UTC, upgrade of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0xf9716c8e311c27decc5858f10b2a2c83ef3d8ce3958cfb242df5415a75b1e6eb](https://etherscan.io/tx/0xf9716c8e311c27decc5858f10b2a2c83ef3d8ce3958cfb242df5415a75b1e6eb), implementations: [0x1C90963D451316E3DBFdD5A30354EE56C29016EB](https://etherscan.io/address/0x1C90963D451316E3DBFdD5A30354EE56C29016EB#code) ([diff](https://disco.l2beat.com/diff/eth:0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF/eth:0x1C90963D451316E3DBFdD5A30354EE56C29016EB))
- 2024-02-29 09:56 UTC, upgrade of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0x4e7b5b82e00b92a5b0380e3a47801760a35f00462793f28926184e984cddc478](https://etherscan.io/tx/0x4e7b5b82e00b92a5b0380e3a47801760a35f00462793f28926184e984cddc478), implementations: [0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF](https://etherscan.io/address/0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF#code) ([diff](https://disco.l2beat.com/diff/eth:0x1c952514f0353d84d9ad35BcfB8E9Ea979289031/eth:0xaEbA6c3042B463DfAA6A2DFA96486D5A92186cFF))
- 2024-02-24 22:25 UTC, deployment of [L2OutputOracle](https://etherscan.io/address/0x826D1B0D4111Ad9146Eb8941D7Ca2B6a44215c76#code): transaction [0x6294e04e136d66468e369543e2789863e2f036ab8e80d473d6808e414c3e233a](https://etherscan.io/tx/0x6294e04e136d66468e369543e2789863e2f036ab8e80d473d6808e414c3e233a), implementations: [0x1c952514f0353d84d9ad35BcfB8E9Ea979289031](https://etherscan.io/address/0x1c952514f0353d84d9ad35BcfB8E9Ea979289031#code)

Contains a list of proposed state roots which Proposers assert to be a result of block execution. Currently only the PROPOSER address can submit new state roots.
- Roles:
  - **admin**: ProxyAdmin; ultimately BlastMultisig 1
  - **challenger**: BlastMultisig 1
  - **proposer**: EOA 1

Can be upgraded by: BlastMultisig 1 with 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).