L2BEAT Bridges is a work in progress. You might find incomplete research or inconsistent naming. Join our discord to suggest improvements!

Hop logoHop


...


Tokens:

Description

Hop is a Liquidity Network that facilitates fast withdrawals and L2-->L2 token transfer via optimistic message passing.

If you find something wrong on this page you can submit an issue or edit the information.

Risk summary

Note: This project's overview requires more research and might not present accurate information. If you want to contribute you can edit the information on Github. Alternatively you contact the project team on Twitter and encourage them to contribute a PR.

Technology

Principle of operation

Hop is a Liquidity Network with ability to facilitate fast transfers using Ethereum as a settlement layer. It uses a technical hToken and AMM between hToken and canonical token on a destination chain to facilitate token transfers. Users are isolated from individual risks related to destination chains.

Optimistic Validation with fallback to native bridge

Messages announcing token withdrawals are sent from the source to the destination chain using native AMB (Arbitrary Messaging Bridge) to Ethereum for a given chain source chain. Depending on a chain, these can be slow, e.g. 7-days for Optimistic Rollups. Designated actors called Bonders "pre-announce" the incoming transfer of a message bundle to the destination chain. For 24 hours anyone can challenge the validity of the message bundle. If left unchallenged, the bundle is assumed to be valid and Bonder can remove the collateral which make all withdrawals from this bundle to settle against bridge funds. If challenged, the Bonder's collateral is locked in a bridge until the native message arrives and challenge is resolved.

  • Users can be censored if AMB of the destination chain censors the message.

  • Funds can be stolen if Bonder submits invalid message bundle and is left unchallenged for 24 hours.

Destination tokens are upgradeable

Note: This section requires more research and might not present accurate information.

Tokens transferred end up as "representation tokens" some of them may be upgradable.

  • Funds can be stolen if destination token contract is maliciously upgraded (CRITICAL).

Permissioned Addresses

The system uses the following set of permissioned addresses:

Timelock for Hop Governance 0x22e3…96e7

Sets bridge parameters including bond size, challenge period length, etc... Manages whitelist of Bonders.

Hop MultiSig Participants 0x9f8d…7f070x404c…E62D0xEb34…2F62

Participants of the 2/3 Hop MultiSig.

Smart Contracts

The system consists of the following smart contracts:

L1_ERC20_Bridge 0x3666…f18a

USDC Bridge. This contract stores the following tokens: USDC.

L1_ERC20_Bridge 0x3d4C…EDd1

DAI Bridge. This contract stores the following tokens: DAI.

L1_ERC20_Bridge 0x3E4a…20B6

USDT Bridge. This contract stores the following tokens: USDT.

L1_ERC20_Bridge 0x22B1…1cc2

MATIC Bridge. This contract stores the following tokens: MATIC.

L1_ETH_Bridge 0xb890…727f

ETH Bridge. This contract stores the following tokens: ETH.

L1_HOP_Bridge 0x914f…4273

HOP Bridge. This contract stores the following tokens: HOP.

L1_ERC20_Bridge 0x8932…8b96

SNX Bridge. This contract stores the following tokens: SNX.