Should the Lido DAO recognize the wstETH Bridge Endpoints on Mantle as canonical?

The proposal is to recognize the wstETH token bridging endpoints for Mantle by the Lido DAO as canonical. If Snapshot passes, the Lido DAO will control the endpoints of wstETH token contract (including the token contract on Mantle itself) as a proxy admin. Lido DAO will only have the upgrade authority of the wstETH proxy contract, and will not be able to manage the native bridge itself.

The Mantle Core Contributor Team is submitting this proposal to the community for the deployment of wstETH on Mantle.

Mantle Network is an optimistic Ethereum layer-2 (L2) solution with an EVM-compatible execution environment. Mantle is DAO-governed and employs a modular approach to execution, consensus, settlement, and data availability. In addition to a burgeoning ecosystem with 110+ dApps and counting, Mantle counts among its partners Game7, HyperPlay, EduDAO, Sozu Haus, and EigenLayer. The DAO-led community-driven Mantle possesses one of the largest on-chain treasuries — and the largest when discounting native tokens — including nearly 270K ETH/wstETH/WETH, priming it to be a major player in ETH LST and LSDFi.

Motivation

Demand for Lido (w)stETH is significantly driven by its utility within major ecosystems, which are leveraging its composability in various DeFi protocols. Notably, wstETH’s overwhelming market share of staked ETH enhances its desirability. Additionally, wstETH’s versatility, being used for a range of DeFi applications including collateral, lending, farming, indexing, minting, vaults, and stables, amplifies its demand further. Mantle aims to leverage this demand for ETH liquid staking tokens and make wstETH one of the core building blocks of the Mantle ecosystem, as well as a core asset of its treasury to sustainably grow its protocol-owned liquidity (POL).

wstETH has already been deployed onto Mantle via the native bridge. This proposed new deployment will be replacing the existing wstETH with a one-way migration pool opened for users to migrate.

• Solution smart contracts
  • GitHub - mantlenetworkio/lido-l2

The proposed components utilize Mantle’s native bridge instance for the message transfer. The token’s upgradeability is possible, due to the token proxy admin being set to Lido DAO and separate from the bridge admin (Mantle) instance. This approach aligns with the unofficial guidelines presented by NEW (Network Expansion Workgroup) and is future-ready for wstETH. As such, neither the bridge or Lido DAO take any additional fees from users. The regular gas fees required for transaction execution will still be charged to the user. In case of an emergency, Lido Emergency Breaks multisig will be used to pause the deposits and withdrawals only for the wstETH transfers. In order to resume the bridging activity for wstETH, there will be a need for a Lido DAO on chain vote on Ethereum mainnet.

Audits

To better form an opinion you may consider reading through the following audit reports.

• Governance crosschain bridges (OptimismBridgeExecutor)
• wstETH on Mantle (L1ERC20TokenBridge, L2ERC20TokenBridge, ERC20BridgedPermit)

Contracts

• Mainnet contracts:
  • L1ERC20TokenBridge Impl: 0x6fBBe1Af52D22557D7F161Dc5952E306F4742e23
  • L1ERC20TokenBridge Proxy: 0x2D001d79E5aF5F65a939781FE228B267a8Ed468B
  • ERC20Bridged Impl: 0x1FaBaAec88198291A4efCc85Cabb33a3785165ba
  • ERC20Bridged Proxy: 0x458ed78EB972a369799fb278c0243b25e5242A83
  • L2ERC20TokenBridge Impl: 0xf10A7ffC613a9b23Abc36167925A375bf5986181
  • L2ERC20TokenBridge Proxy: 0x9c46560D6209743968cC24150893631A39AfDe4d
  • OptimismBridgeExecutor: 0x3a7B055BF88CdC59D20D0245809C6E6B3c5819dd

Ownership, roles, and levers Mainnet setup

• for the Mantle Governance Bridge Executor (OptimismBridgeExecutor contract is used)
  • getEthereumGovernanceExecutor is the Lido DAO Agent
• A bridge admin and role holder on L1 is the Lido DAO Agent
  • Proxy admin for L1ERC20Bridge
  • DEFAULT_ADMIN_ROLE for L1ERC20Bridge
  • WITHDRAWALS_DISABLER_ROLE for L1ERC20Bridge
  • WITHDRAWALS_ENABLER_ROLE for L1ERC20Bridge
  • DEPOSITS_DISABLER_ROLE for L1ERC20Bridge
  • DEPOSITS_ENABLER_ROLE for L1ERC20Bridge
• A bridge admin and role holder on L2 is the Mantle Governance Bridge Executor
  • Proxy admin for L2ERC20TokenBridge
  • DEFAULT_ADMIN_ROLE for L2ERC20TokenBridge
  • WITHDRAWALS_DISABLER_ROLE for L2ERC20TokenBridge
  • WITHDRAWALS_ENABLER_ROLE for L2ERC20TokenBridge
  • DEPOSITS_DISABLER_ROLE for L2ERC20TokenBridge
  • DEPOSITS_ENABLER_ROLE for L2ERC20TokenBridge
• for the proposed wstETH token on L2 (ERC20BridgedPermit)
  • Proxy admin is the Mantle Governance Bridge Executor
• Emergency breaks msig on L1 is 0x73b047fe6337183A454c5217241D780a932777bD, 3/5 threshold:
  • WITHDRAWALS_DISABLER_ROLE for L1ERC20TokenBridge
  • DEPOSITS_DISABLER_ROLE for L1ERC20TokenBridge
• Emergency breaks msig on L2 is a new one 0xa8579D42E34398267dE16e6eeeCdb7ED0EFF953C inheriting the same EOAs as for L1, 3/5 threshold:
  • WITHDRAWALS_DISABLER_ROLE for L2ERC20TokenBridge
  • DEPOSITS_DISABLER_ROLE for L2ERC20TokenBridge
• An initial deployer has no remaining permissions and levers assigned