# LightLink

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

## Summary

**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. There is no data availability bridge. Consequence: projects without a data availability bridge fully rely on single entities (the sequencer) to honestly rely available data roots on Ethereum. A malicious sequencer can collude with the proposer to finalize an unavailable state, which can cause loss of funds. Learn more about the [recategorisation](https://medium.com/l2beat/framework-update-l2-projects-recategorisation-5d43b0d1fe50).

- Total Value Secured: $634.67 K (-12.4% compared to seven days ago; canonically bridged $634.67 K, natively minted $0.00, externally bridged $0.00; 0.00% with additional trust assumptions compared to the tokens involved and the Stage assigned to the project's canonical messaging bridge)
  - **Warning:** The LL token associated with LightLink accounts for 60.1% of the TVS! (sentiment: warning)
- TVS by asset: ETH & derivatives $212.22 K (33.4%), Stablecoins $40.37 K (6.36%), BTC & derivatives $120.08 (0.01%), Other $381.96 K (60.1%)
- Associated tokens: LL: $381.95 K (60.1% of TVS)
- Past day UOPS: 0.27 (-3.84% compared to seven days ago)
- Type: Other
- Purpose: Universal
- Host chain: Ethereum
- Chain ID: 1890

### Risks

- Sequencer failure: Self sequence (sentiment: good)
- State validation: None (sentiment: bad)
- Data availability: External (sentiment: bad)
- Exit window: None (sentiment: bad)
- Proposer failure: Cannot withdraw (sentiment: bad)

### About

LightLink is a project that lets dApps and enterprises offer users instant, gasless transactions.

### Links

- Website: https://lightlink.io
- Bridge: https://phoenix.lightlink.io/apps
- Docs: https://docs.lightlink.io
- Explorer: https://phoenix.lightlink.io
- Repository: https://github.com/lightlink-network
- Social: https://twitter.com/lightlinkchain, https://discord.com/invite/lightlinkchain, https://t.me/lightlinkll, https://linkedin.com/company/lightlinkchain
- Contracts explorer (Disco): https://disco.l2beat.com/ui/p/lightlink

### Badges

- EVM: This project uses the Ethereum Virtual Machine to run its smart contracts and supports the Solidity programming language
- Celestia: This project is posting its data to Celestia

## Value Secured

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

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

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

## Activity

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

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

## Risk summary

### Funds can be stolen if

1. validators decide to mint more tokens than there are locked on Ethereum thus preventing some existing holders from being able to bring their funds back to Ethereum,
2. validators relay a withdraw request that wasn't originated on the source chain,
3. the publisher posts an invalid block header on Ethereum.

### Funds can be frozen if

4. celestia becomes unavailable and transaction data cannot be retrieved.

### Users can be censored if

5. validators decide to not mint tokens after observing an event on Ethereum.

## Risk analysis

### Sequencer failure

Self sequence (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 (sentiment: bad)

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

### Data availability

External (sentiment: bad)

Proof construction and state derivation fully rely on data that is posted on Celestia. Sequencer tx roots are not checked against the Blobstream bridge data roots onchain, but L2 nodes can verify data availability by running a Celestia light client.

### 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.

## Data availability

### Data is posted to Celestia

LightLink uses Celestia for data availability. Transaction data is posted to Celestia, and block headers containing Celestia data pointers are posted to the CanonicalStateChain contract on Ethereum L1.

There is no automatic fallback mechanism to Ethereum for data availability. If Celestia becomes unavailable, the chain relies entirely on Celestia for transaction data recovery.

**Risks**

- Funds can be frozen if celestia becomes unavailable and transaction data cannot be retrieved.

**References**

- [LightLink Celestia Integration](https://docs.lightlink.io/lightlink-protocol/achitecture-and-design/lightlink-protocol-deep-dive#id-2-data-availability-layer)

## State validation

The project implements an incomplete and non-functional proof system.

### Challenges

LightLink chain state roots are periodically posted to Ethereum through a CanonicalStateChain contract on L1 as block headers that also contain Celestia data pointers. After the challenge window of 5d, the published state root is assumed to be correct. During the challenge window, anyone can challenge a block header against some basic validity checks. The challenge fee required is 1.5 ETH.
Once challenged, the permissioned defender can respond within 2d to the challenge, by providing the L2 header and the previous L2 header. If the defender does not respond,
the block header is considered invalid, the canonical state chain is rolled back to the previous state root, and the challenger can claim back the challenge fee. If the defender successfully responds, the challenger loses the challenge fee to the defender.
Since only the block header can be challenged and not the state transition, the system is vulnerable to invalid state roots. Moreover, state roots are not used for ERC20 withdrawals from the LightLinkERC20Bridge.
Users can deposit tokens on the LightLink chain by sending them to the L1BridgeRegistry contract on Ethereum L1. On the LightLink chain, ERC20 token minting is then authorized by a permissioned set of signers providing signatures as input to the syncDeposit() function on the L2ERC20Predicate contract.
Users can withdraw their funds by submitting a withdraw() transaction to the L2ERC20Predicate contract, which will burn the tokens on the LightLink chain. To then unlock tokens from the bridge on L1, a validator multisig needs to validate the withdrawal based on off-chain validity checks.
Users can exit the network once enough validators have signed off on the withdrawal.
Currently, a minimum of 2 validators is required to sign off on a withdrawal. To deposit the gas token, i.e. ETH, the LightLinkPortal is used which uses the CanonicalStateChain as the source for the state root, and withdrawals follow the usual OP stack process.

**Risks**

- Users can be censored if validators decide to not mint tokens after observing an event on Ethereum.
- Funds can be stolen if validators decide to mint more tokens than there are locked on Ethereum thus preventing some existing holders from being able to bring their funds back to Ethereum.
- Funds can be stolen if validators relay a withdraw request that wasn't originated on the source chain.
- Funds can be stolen if the publisher posts an invalid block header on Ethereum.

**References**

- [LightLink L2 syncDeposit() - L2ERC20Predicate.sol](https://phoenix.lightlink.io/address/0x63105ee97BfB22Dfe23033b3b14A4F8FED121ee9?tab=contract_code)
- [LightLink L1 syncWithdraw()- L1ERC20Predicate.sol](https://etherscan.io/address/0xa8372d6ff00d48a25baa1af16d6a86c936708f4e#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: 2
- Last upgrade: 2y 1mo ago
- Avg upgrade interval: 1y 2mo

- 2024-09-05 13:35 UTC, upgrade of [Challenge](https://etherscan.io/address/0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd#code): transaction [0x4395a7f970de1003c82254f83fbf42c5f11a97842d23ff171be9d0d6c683010b](https://etherscan.io/tx/0x4395a7f970de1003c82254f83fbf42c5f11a97842d23ff171be9d0d6c683010b), implementations: [0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B](https://etherscan.io/address/0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B#code) ([diff](https://disco.l2beat.com/diff/eth:0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC/eth:0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B))
- 2024-09-05 13:31 UTC, upgrade of [CanonicalStateChain](https://etherscan.io/address/0x65E325A22c0F519041db69F5693EbAc3b4AE71bE#code): transaction [0xcc066ac45b2d6527afdb41a5254a2093bcbc6d8e7d8571f6139b08db97f6e50b](https://etherscan.io/tx/0xcc066ac45b2d6527afdb41a5254a2093bcbc6d8e7d8571f6139b08db97f6e50b), implementations: [0xeFE38Bd58ADDf23eFab1FFa16312030384929289](https://etherscan.io/address/0xeFE38Bd58ADDf23eFab1FFa16312030384929289#code) ([diff](https://disco.l2beat.com/diff/eth:0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5/eth:0xeFE38Bd58ADDf23eFab1FFa16312030384929289))
- 2024-09-05 12:55 UTC, deployment of [SystemConfig](https://etherscan.io/address/0x670E1C42A7A5962348138110E3ede3F422c10e2f#code): transaction [0xba247cf6a6837abe69513ffa16c42dd58ef1bf1f418baa8b94cf5b37132ef3a5](https://etherscan.io/tx/0xba247cf6a6837abe69513ffa16c42dd58ef1bf1f418baa8b94cf5b37132ef3a5), implementations: [0x9EC8231132d6722D463077a7cCe1432c3766d9A2](https://etherscan.io/address/0x9EC8231132d6722D463077a7cCe1432c3766d9A2#code)
- 2024-09-05 12:54 UTC, deployment of [L1StandardBridge](https://etherscan.io/address/0xc7a7199bb5F0aA7B54eca90fC793Ec83E5683b0c#code): transaction [0x8139a100e3a2621ada034969254c23a9d541c7b375602cb3121b499cf78e4c08](https://etherscan.io/tx/0x8139a100e3a2621ada034969254c23a9d541c7b375602cb3121b499cf78e4c08), implementations: [0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48](https://etherscan.io/address/0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48#code)
- 2024-09-05 12:54 UTC, deployment of [L1CrossDomainMessenger](https://etherscan.io/address/0xA30eAe91b9184Bb5e14b86Dd10d463F67c699C38#code): transaction [0xd9c97881c92c991d39a0835c10cf0510bae89ffe30887cbeca37cb0ef3df3542](https://etherscan.io/tx/0xd9c97881c92c991d39a0835c10cf0510bae89ffe30887cbeca37cb0ef3df3542), implementations: [0x38104856c02f83f4048c0FBA3D7613042FEAc988](https://etherscan.io/address/0x38104856c02f83f4048c0FBA3D7613042FEAc988#code)
- 2024-09-05 12:54 UTC, deployment of [LightLinkPortal](https://etherscan.io/address/0xB1Fb5A59A738c2df565d79572b0D6f348aE7cADE#code): transaction [0x9481126f85589426739b38363db3992504500651385a858b4aea108aad3d074b](https://etherscan.io/tx/0x9481126f85589426739b38363db3992504500651385a858b4aea108aad3d074b), implementations: [0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD](https://etherscan.io/address/0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD#code)
- 2024-06-04 17:32 UTC, deployment of [Challenge](https://etherscan.io/address/0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd#code): transaction [0x84c616f81289c7637be644c43b7a1bf740daa615896f9bb9d141c3d383c4b6f1](https://etherscan.io/tx/0x84c616f81289c7637be644c43b7a1bf740daa615896f9bb9d141c3d383c4b6f1), implementations: [0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC](https://etherscan.io/address/0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC#code)
- 2024-06-04 17:31 UTC, deployment of [ChainOracle](https://etherscan.io/address/0x2fbD45A4B57379492450c3D5a8fdcaD68336DB04#code): transaction [0x777ffc74cdda4dadf5067e5736ed319792fa6e37c5eab24573e3fd01f33e2334](https://etherscan.io/tx/0x777ffc74cdda4dadf5067e5736ed319792fa6e37c5eab24573e3fd01f33e2334), implementations: [0x79B3E839333a74137e78b0DaF84FC12512a8c704](https://etherscan.io/address/0x79B3E839333a74137e78b0DaF84FC12512a8c704#code)
- 2024-06-04 17:31 UTC, deployment of [CanonicalStateChain](https://etherscan.io/address/0x65E325A22c0F519041db69F5693EbAc3b4AE71bE#code): transaction [0x39c4618d14675071a6b0f6183c7cf605373987d3ed2677426598aa67e5d15e56](https://etherscan.io/tx/0x39c4618d14675071a6b0f6183c7cf605373987d3ed2677426598aa67e5d15e56), implementations: [0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5](https://etherscan.io/address/0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5#code)
- 2023-08-16 03:12 UTC, deployment of [L1ERC20Predicate](https://etherscan.io/address/0x63105ee97BfB22Dfe23033b3b14A4F8FED121ee9#code): transaction [0x2a6786734b18517394bf675986e76ba59c82e093d87180792e3f5287c98af7a0](https://etherscan.io/tx/0x2a6786734b18517394bf675986e76ba59c82e093d87180792e3f5287c98af7a0), implementations: [0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E](https://etherscan.io/address/0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E#code)
- 2023-08-16 02:57 UTC, deployment of [L1BridgeRegistry](https://etherscan.io/address/0x624631881655a310adcF0d1336658Cc977609b72#code): transaction [0xd39a80831c0c0fdc27b6e030d6e1a393b0d3cbc0f8b9d22d0fa2046b33e2fc76](https://etherscan.io/tx/0xd39a80831c0c0fdc27b6e030d6e1a393b0d3cbc0f8b9d22d0fa2046b33e2fc76), implementations: [0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E](https://etherscan.io/address/0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E#code)

## Updates

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

### [2025-07-14 12:45 UTC](https://l2beat.com/layer2s/projects/lightlink?update=008f7ec8) (12 changes)

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

### [2025-04-03 16:12 UTC](https://l2beat.com/layer2s/projects/lightlink?update=e21de4da) (72 changes)

Lightlink moves to opstack (partly).

### [2025-03-07 13:54 UTC](https://l2beat.com/layer2s/projects/lightlink?update=68f2e226) (10 changes)

Some admin / owner permissions moved from EOA to 3/3 Safe (Lightlink is moving to an op stack deployment).

### [2025-03-03 08:56 UTC](https://l2beat.com/layer2s/projects/lightlink?update=7158c97f) (2 changes)

Bridge paused, all ETH moved into a multisig. Probably connected to them [moving their infra to the op stack fork](https://x.com/LightLinkChain/status/1895145558777491655).

Put project under review and added warning.

### [2025-01-16 08:12 UTC](https://l2beat.com/layer2s/projects/lightlink?update=04603634) (2 changes)

challengeWindow (the effective challenge period) increased to 5d.

### [2024-09-05 15:26 UTC](https://l2beat.com/layer2s/projects/lightlink?update=8a4f1b33) (high severity, 6 changes)

Small upgrade:

#### Challenge.sol
- new `finalizationSeconds()` returns challengePeriod + challengeWindow

#### CanonicalStateChain.sol
- new `OutputProposed` event for each new output root (on `pushBlock()`)
- `output root = keccack(version_hash || keccack(state_root || withdrawal_root || latest_block_hash))`
- new `getL2Output()` returns outputRoot, timestamp

### [2024-06-10 11:17 UTC](https://l2beat.com/layer2s/projects/lightlink?update=1af1e884) (8 changes)

Provide description of changes. This section will be preserved.

## Permissions

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

### Ethereum

#### Roles

##### Validators

Addresses: [0x12eCE4AA73ee8ea958bE327daE41Dd785c997118](https://etherscan.io/address/0x12eCE4AA73ee8ea958bE327daE41Dd785c997118), [0x6f933814903561F79137099587737DFB24c6E86D](https://etherscan.io/address/0x6f933814903561F79137099587737DFB24c6E86D), [0xB44C32Dd1ec374224eED43FD827EBE64db16b0df](https://etherscan.io/address/0xB44C32Dd1ec374224eED43FD827EBE64db16b0df), [0xaB0DDC4B1Fc1F24D4F7F67ab87B5dD8e5e0c5AC9](https://etherscan.io/address/0xaB0DDC4B1Fc1F24D4F7F67ab87B5dD8e5e0c5AC9), [0xc8225cA10F570d4d7aD6cdb6F0bfEb683dc7C938](https://etherscan.io/address/0xc8225cA10F570d4d7aD6cdb6F0bfEb683dc7C938)

Permissioned set of actors that can validate withdrawals from the bridge. Each validators has a voting power assigned that determines the weight of their vote. Currently, the threshold is set to 50.00% of the total voting power.

#### Actors

##### Lightlink Multisig 2

Addresses: [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7)

A Multisig with 3/3 threshold.
- Can upgrade **with no delay**
  - Challenge
  - ChainOracle
  - CanonicalStateChain
  - SystemConfig
  - L1CrossDomainMessenger
  - LightLinkPortal
  - L1StandardBridge
- Can interact with Challenge
  - it can disable L2 header challenges and DA challenges, it can update the challenge period (3h and 3 weeks), update the challenger fee (between 0.01 and 10 ether), update the challenge reward (between 0.01 and 10 ether), update the defender address, update the DA namespace, update the DA oracle, disable header challenges and set the maximum bundle size
- Can interact with CanonicalStateChain
  - it can update the maximum number of Celestia pointers a block can have, change the challenge contract used for rollbacks and update the publisher address
- Can interact with LightLinkPortal
  - it can pause the chain and update the gas token

Participants (3): [0x67Ad58C203cEB0f39026270D920cc0f29eB4eE91](https://etherscan.io/address/0x67Ad58C203cEB0f39026270D920cc0f29eB4eE91), [0xdE2552948aacb82dCa7a04AffbcB1B8e3C97D590](https://etherscan.io/address/0xdE2552948aacb82dCa7a04AffbcB1B8e3C97D590), [0x6F17201F241231f183CE52212e4C47B009036421](https://etherscan.io/address/0x6F17201F241231f183CE52212e4C47B009036421)

##### Lightlink Multisig 1

Addresses: [0x3345702FeA1669Efa1e085610A62F89d159Bc0c8](https://etherscan.io/address/0x3345702FeA1669Efa1e085610A62F89d159Bc0c8)

Custom multisig implementation with a hardcoded n/2+1 threshold.
- Can interact with L1BridgeRegistry
  - can remove and add validators, update their voting power, and change the required threshold

##### EOA 1

Addresses: [0x514F8211B64f0620349659DeaDB5911a9896E7EC](https://etherscan.io/address/0x514F8211B64f0620349659DeaDB5911a9896E7EC)

- Can interact with CanonicalStateChain
  - it can publish new block headers, which both includes pointers to Celestia DA and the state root for withdrawals, meaning that sequencing and state updates are not decoupled

## Smart contracts

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

### Ethereum

#### L1CrossDomainMessenger

Addresses: [0xA30eAe91b9184Bb5e14b86Dd10d463F67c699C38](https://etherscan.io/address/0xA30eAe91b9184Bb5e14b86Dd10d463F67c699C38#code), [0x38104856c02f83f4048c0FBA3D7613042FEAc988](https://etherscan.io/address/0x38104856c02f83f4048c0FBA3D7613042FEAc988#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 12:54 UTC, deployment of [L1CrossDomainMessenger](https://etherscan.io/address/0xA30eAe91b9184Bb5e14b86Dd10d463F67c699C38#code): transaction [0xd9c97881c92c991d39a0835c10cf0510bae89ffe30887cbeca37cb0ef3df3542](https://etherscan.io/tx/0xd9c97881c92c991d39a0835c10cf0510bae89ffe30887cbeca37cb0ef3df3542), implementations: [0x38104856c02f83f4048c0FBA3D7613042FEAc988](https://etherscan.io/address/0x38104856c02f83f4048c0FBA3D7613042FEAc988#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**: Lightlink Multisig 2

Can be upgraded by: Lightlink Multisig 2 with no delay

#### L1StandardBridge

Addresses: [0xc7a7199bb5F0aA7B54eca90fC793Ec83E5683b0c](https://etherscan.io/address/0xc7a7199bb5F0aA7B54eca90fC793Ec83E5683b0c#code), [0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48](https://etherscan.io/address/0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 12:54 UTC, deployment of [L1StandardBridge](https://etherscan.io/address/0xc7a7199bb5F0aA7B54eca90fC793Ec83E5683b0c#code): transaction [0x8139a100e3a2621ada034969254c23a9d541c7b375602cb3121b499cf78e4c08](https://etherscan.io/tx/0x8139a100e3a2621ada034969254c23a9d541c7b375602cb3121b499cf78e4c08), implementations: [0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48](https://etherscan.io/address/0xCE7Ab4b8471A3119aabB63101b7C7B999464Fc48#code)

The main entry point to deposit ERC20 tokens from host chain to this chain.
- Roles:
  - **admin**: Lightlink Multisig 2

Can be upgraded by: Lightlink Multisig 2 with no delay

#### Challenge

Addresses: [0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd](https://etherscan.io/address/0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd#code), [0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B](https://etherscan.io/address/0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 13:35 UTC, upgrade of [Challenge](https://etherscan.io/address/0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd#code): transaction [0x4395a7f970de1003c82254f83fbf42c5f11a97842d23ff171be9d0d6c683010b](https://etherscan.io/tx/0x4395a7f970de1003c82254f83fbf42c5f11a97842d23ff171be9d0d6c683010b), implementations: [0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B](https://etherscan.io/address/0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B#code) ([diff](https://disco.l2beat.com/diff/eth:0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC/eth:0x4Fc6a6A2e3864709ae6AdCf29280dA01c95Aa10B))
- 2024-06-04 17:32 UTC, deployment of [Challenge](https://etherscan.io/address/0x1c1271bEE8556918092dA9238FcC77ee8be4b5Cd#code): transaction [0x84c616f81289c7637be644c43b7a1bf740daa615896f9bb9d141c3d383c4b6f1](https://etherscan.io/tx/0x84c616f81289c7637be644c43b7a1bf740daa615896f9bb9d141c3d383c4b6f1), implementations: [0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC](https://etherscan.io/address/0x2785D4Af59bf299C1f2DBC5132E72B2eE015B3aC#code)

Allows to challenge block headers. Each challenge requires the payment of a challenger fee. DA challenges are enabled: false. Header challenges are enabled: true. L2 Header challenges are enabled: false.
- Roles:
  - **admin**: Lightlink Multisig 2
  - **owner**: Lightlink Multisig 2

Can be upgraded by: Lightlink Multisig 2 with no delay

#### ChainOracle

Addresses: [0x2fbD45A4B57379492450c3D5a8fdcaD68336DB04](https://etherscan.io/address/0x2fbD45A4B57379492450c3D5a8fdcaD68336DB04#code), [0x79B3E839333a74137e78b0DaF84FC12512a8c704](https://etherscan.io/address/0x79B3E839333a74137e78b0DaF84FC12512a8c704#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-06-04 17:31 UTC, deployment of [ChainOracle](https://etherscan.io/address/0x2fbD45A4B57379492450c3D5a8fdcaD68336DB04#code): transaction [0x777ffc74cdda4dadf5067e5736ed319792fa6e37c5eab24573e3fd01f33e2334](https://etherscan.io/tx/0x777ffc74cdda4dadf5067e5736ed319792fa6e37c5eab24573e3fd01f33e2334), implementations: [0x79B3E839333a74137e78b0DaF84FC12512a8c704](https://etherscan.io/address/0x79B3E839333a74137e78b0DaF84FC12512a8c704#code)

Used to challenge L2 block headers. If L2 block header challenges are inactive, this contract is not used.
- Roles:
  - **admin**: Lightlink Multisig 2

Can be upgraded by: Lightlink Multisig 2 with no delay

#### L1BridgeRegistry

Addresses: [0x624631881655a310adcF0d1336658Cc977609b72](https://etherscan.io/address/0x624631881655a310adcF0d1336658Cc977609b72#code), [0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E](https://etherscan.io/address/0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E#code) (Implementation (Upgradable)), [0x0000000000000000000000000000000000000000](https://etherscan.io/address/0x0000000000000000000000000000000000000000#code) (Admin)

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

- 2023-08-16 02:57 UTC, deployment of [L1BridgeRegistry](https://etherscan.io/address/0x624631881655a310adcF0d1336658Cc977609b72#code): transaction [0xd39a80831c0c0fdc27b6e030d6e1a393b0d3cbc0f8b9d22d0fa2046b33e2fc76](https://etherscan.io/tx/0xd39a80831c0c0fdc27b6e030d6e1a393b0d3cbc0f8b9d22d0fa2046b33e2fc76), implementations: [0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E](https://etherscan.io/address/0xC48F0e7C3c4E385ae84B4f678A0482E00208cf3E#code)

The L1BridgeRegistry contract is used to store the address of the LightLink multisig and the address and voting power of the validators managing the bridge.
- Roles:
  - **multisig**: Lightlink Multisig 1

#### L1ERC20Predicate (escrow)

Addresses: [0x63105ee97BfB22Dfe23033b3b14A4F8FED121ee9](https://etherscan.io/address/0x63105ee97BfB22Dfe23033b3b14A4F8FED121ee9#code), [0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E](https://etherscan.io/address/0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E#code) (Implementation (Upgradable)), [0x0000000000000000000000000000000000000000](https://etherscan.io/address/0x0000000000000000000000000000000000000000#code) (Admin)

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

- 2023-08-16 03:12 UTC, deployment of [L1ERC20Predicate](https://etherscan.io/address/0x63105ee97BfB22Dfe23033b3b14A4F8FED121ee9#code): transaction [0x2a6786734b18517394bf675986e76ba59c82e093d87180792e3f5287c98af7a0](https://etherscan.io/tx/0x2a6786734b18517394bf675986e76ba59c82e093d87180792e3f5287c98af7a0), implementations: [0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E](https://etherscan.io/address/0xa8372d6FF00d48A25BaA1AF16d6a86C936708f4E#code)

ERC20 token escrow contract. It is validated by external validators, according to the L1BridgeRegistry values.

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

#### CanonicalStateChain

Addresses: [0x65E325A22c0F519041db69F5693EbAc3b4AE71bE](https://etherscan.io/address/0x65E325A22c0F519041db69F5693EbAc3b4AE71bE#code), [0xeFE38Bd58ADDf23eFab1FFa16312030384929289](https://etherscan.io/address/0xeFE38Bd58ADDf23eFab1FFa16312030384929289#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 13:31 UTC, upgrade of [CanonicalStateChain](https://etherscan.io/address/0x65E325A22c0F519041db69F5693EbAc3b4AE71bE#code): transaction [0xcc066ac45b2d6527afdb41a5254a2093bcbc6d8e7d8571f6139b08db97f6e50b](https://etherscan.io/tx/0xcc066ac45b2d6527afdb41a5254a2093bcbc6d8e7d8571f6139b08db97f6e50b), implementations: [0xeFE38Bd58ADDf23eFab1FFa16312030384929289](https://etherscan.io/address/0xeFE38Bd58ADDf23eFab1FFa16312030384929289#code) ([diff](https://disco.l2beat.com/diff/eth:0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5/eth:0xeFE38Bd58ADDf23eFab1FFa16312030384929289))
- 2024-06-04 17:31 UTC, deployment of [CanonicalStateChain](https://etherscan.io/address/0x65E325A22c0F519041db69F5693EbAc3b4AE71bE#code): transaction [0x39c4618d14675071a6b0f6183c7cf605373987d3ed2677426598aa67e5d15e56](https://etherscan.io/tx/0x39c4618d14675071a6b0f6183c7cf605373987d3ed2677426598aa67e5d15e56), implementations: [0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5](https://etherscan.io/address/0xd8C81A0CB0044fC45B51531A8dcc48Ed385937B5#code)

Contains the logic to update the state of the chain, and apply rollbacks based on an external challenger contract. If a block header is challenged and rolled back, then all subsequent blocks are also rolled back.
- Roles:
  - **admin**: Lightlink Multisig 2
  - **owner**: Lightlink Multisig 2
  - **publisher**: EOA 1

Can be upgraded by: Lightlink Multisig 2 with no delay

#### SystemConfig

Addresses: [0x670E1C42A7A5962348138110E3ede3F422c10e2f](https://etherscan.io/address/0x670E1C42A7A5962348138110E3ede3F422c10e2f#code), [0x9EC8231132d6722D463077a7cCe1432c3766d9A2](https://etherscan.io/address/0x9EC8231132d6722D463077a7cCe1432c3766d9A2#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 12:55 UTC, deployment of [SystemConfig](https://etherscan.io/address/0x670E1C42A7A5962348138110E3ede3F422c10e2f#code): transaction [0xba247cf6a6837abe69513ffa16c42dd58ef1bf1f418baa8b94cf5b37132ef3a5](https://etherscan.io/tx/0xba247cf6a6837abe69513ffa16c42dd58ef1bf1f418baa8b94cf5b37132ef3a5), implementations: [0x9EC8231132d6722D463077a7cCe1432c3766d9A2](https://etherscan.io/address/0x9EC8231132d6722D463077a7cCe1432c3766d9A2#code)

Fork of the OP stack's SystemConfig. It link to the main portal contract and stores a 'start block' number. Both values are currently unused. Most importantly, it does NOT contain the resource configuration info.
- Roles:
  - **admin**: Lightlink Multisig 2

Can be upgraded by: Lightlink Multisig 2 with no delay

#### LightLinkPortal (escrow)

Addresses: [0xB1Fb5A59A738c2df565d79572b0D6f348aE7cADE](https://etherscan.io/address/0xB1Fb5A59A738c2df565d79572b0D6f348aE7cADE#code), [0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD](https://etherscan.io/address/0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD#code) (Implementation (Upgradable)), [0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7](https://etherscan.io/address/0x8D43A0d17F9883ED0b2Ddf89761d3cc74a5fC6C7#code) (Admin)

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

- 2024-09-05 12:54 UTC, deployment of [LightLinkPortal](https://etherscan.io/address/0xB1Fb5A59A738c2df565d79572b0D6f348aE7cADE#code): transaction [0x9481126f85589426739b38363db3992504500651385a858b4aea108aad3d074b](https://etherscan.io/tx/0x9481126f85589426739b38363db3992504500651385a858b4aea108aad3d074b), implementations: [0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD](https://etherscan.io/address/0x3B1ADfe78B9B4107c47267AE97e2a91b1D8811fD#code)

Main contract to deposit ETH and handle L1 to L2 messages. It also allows to prove and finalize withdrawals. It also stores the resource configuration for the chain.
- Roles:
  - **admin**: Lightlink Multisig 2
  - **owner**: Lightlink Multisig 2

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

Can be upgraded by: Lightlink Multisig 2 with no delay

#### RLPReader

Addresses: [0xEe055Dddc462e35521005e1b00FcEFd78E1fc9E2](https://etherscan.io/address/0xEe055Dddc462e35521005e1b00FcEFd78E1fc9E2#code)