Gnosis Bridge

The Gnosis bridge is comprised of two standard multisig-validated token bridges (Omni and xDAI) with similar architecture and validators. While the xDAI bridge is only used for bridging DAI-related tokens (xDAI is Gnosis Chains gas token), the Omni bridge can be used to bridge many other ERC-20 tokens. Both bridges on ethereum are served by external validators that sign bridge messages via custom multisigs. Assets that are locked in one of the escrows on ethereum can be ‘invested’ by permissioned actors to generate yield. In the case of DAI / sDAI (Spark protocol), the yield is handed down to sDAI users on Gnosis Chain. The addition of Hashi (EVM Hash Oracle Aggregator) and light clients for message validation is being tested but remains optional for now.

Incoming messages to Ethereum are validated by Multisigs with publicly known entities as their signers. The DAI bridge validators are validated by the 4/7 BridgeValidators_DAI Multisig and the Omni bridge by the 4/7 BridgeValidators_Omni Multisig. Only messages signed by at least the threshold amount of validators from the respective multisig are accepted for releasing funds from the escrow contract or for executing messages.

Users receive wrapped ERC677 tokens on Gnosis Chain. There’s a separate bridge for Dai.

User assets in the bridge escrow are not locked and can be moved by permissioned actors. This is usually done to generate yield, which can then be forwarded to the users.