Architecture

MultiGov employs a hub-and-spoke model to enable cross-chain governance, utilizing Wormhole's interoperability infrastructure for secure cross-chain communication. This architecture allows for coordinated decision-making across multiple blockchain networks while maintaining a central point of coordination.

Key Components

Hub Chain:

• HubGovernor: Central governance contract managing proposals and vote tallying.

• HubVotePool: Receives aggregated votes from spokes and submits them to HubGovernor.

• HubMessageDispatcher: Relays approved proposal executions to spoke chains.

• HubProposalExtender: Allows trusted actors to extend voting periods if needed.

• HubProposalMetadata: Helper contract returning proposalId and vote start for HubGovernor proposals.

• HubEvmSpokeAggregateProposer: Aggregates cross-chain voting weight for an address and proposes via the HubGovernor if eligible.

Spoke Chains:

• SpokeVoteAggregator: Collects votes on the spoke chain and forwards them to the hub.

• SpokeMessageExecutor: Receives and executes approved proposals from the hub.

• SpokeMetadataCollector: Fetches proposal metadata from the hub for spoke chain voters.

• SpokeAirlock: Acts as governance's "admin" on the spoke, has permissions and its own treasury.

System Workflow

1. Proposal Creation:

   • A user creates a proposal through the HubEvmSpokeAggregateProposer, which checks eligibility across chains, or directly on the HubGovernor via the propose method.

   • The proposal is submitted to the HubGovernor if the user meets the proposal threshold.

2. Proposal Metadata Distribution:

   • HubProposalMetadata creates a custom view method to be queried for use in the SpokeMetadataCollector.

   • SpokeMetadataCollector on each spoke chain queries HubProposalMetadata for proposal details.

3. Voting Process:

   • Users on spoke chains vote through their respective SpokeVoteAggregators.

   • SpokeVoteAggregators send aggregated votes to the HubVotePool via Wormhole.

   • HubVotePool submits the aggregated votes to the HubGovernor.

4. Vote Tallying and Proposal Execution:

   • HubGovernor tallies votes from all chains.

   • If quorum is reached and there are more for votes then against votes, the vote passes and is queued for execution.

   • After the timelock delay, the proposal can be executed on the hub chain.

   • For cross-chain actions, a proposal should call the dispatch method in the HubMessageDispatcher which sends execution messages to the relevant spoke chains.

   • SpokeMessageExecutors on each spoke chain receive and execute the approved actions through their respective SpokeAirlocks.

Cross-Chain Communication

• Wormhole's infrastructure is used for all cross-chain messaging, ensuring security and reliability.

• Queries for vote aggregation and proposal metadata use Wormhole's cross-chain state read system (Queries).

• Cross-chain proposal execution messages are sent via Wormhole's custom relaying system.

Security Measures

• Vote Weight Window: Implements a moving window for vote weight checkpoints to mitigate cross-chain double voting.

  • Proposal Extension: HubProposalExtender allows for extending voting periods by a trusted actor in the case of network issues or high-stakes decisions.

• Timelock: A timelock period between proposal approval and execution allows for additional security checks and community review.

• Wormhole Verification: All cross-chain messages are verified using Wormhole's secure messaging protocol.

Detailed Architecture Diagram

This architecture ensures that MultiGov can operate securely and efficiently across multiple chains, allowing for truly decentralized and cross-chain governance while maintaining a unified decision-making process.