Halt Bridge in Case of Emergency

In a case of an emergency (e.g. a exploitable vulnerability found), the bridge needs to be halted so that no messages can be processed.

Halting Mechanism

The bridge is halted through a storage item in each Snowbridge pallet called OperatingMode .

Possible operating mode states are:

• Normal

• Halted (RejectingOutboundMessages for the system pallet)

If the operating mode is set to Halted, no bridge messages will be processed. Each pallet needs to be disabled individually. Here are the pallets that need to be disabled, with the call hash to do so:

• Ethereum client pallet: 0x520301

• Inbound queue pallet: 0x500101

• Outbound queue pallet: 0x510001

• Ethereum system pallet: 0x530101

These extrinsics should be done from the relay chain, descending to the BridgeHub parachain origin, similar to the force beacon checkpoint call.

If the bridge was halted, no messages will be processed. When the operating mode is changed to normal messages will be continue being processed.