Gnosis Bridges Speed Up Ethereum Deposits With Fast Confirmation Rule

Faster deposits on Gnosis bridges using Ethereum Fast Confirmation Rule

Gnosis Chain announced on October 8 that its xDAI bridge and Omnibridge now confirm deposits from Ethereum in about 12 seconds, down from at least roughly 13 minutes. The change uses Ethereum's Fast Confirmation Rule, or FCR, instead of waiting for full finality.

The update applies to all transfers from Ethereum by default. Users and apps do not need to make any changes.

However, the faster confirmation does not guarantee immediate end-to-end delivery. Bridge validator processing and signature collection can still add time.

How the Fast Confirmation Rule works

Under FCR, bridge validators process Ethereum blocks marked as safe by their own nodes rather than waiting for finalized blocks. Finalized blocks represent a higher level of confirmation that takes longer to reach.

Gnosis's documentation states that FCR's security guarantee depends on at least 75% of Ethereum's staked ether being honest and participating, with validator votes reaching honest validators within about eight seconds. A finalized block offers different protection: reversing it would require at least one-third of all stake to be slashed.

The bridge contracts themselves remain unchanged.

Fallback to finality during network issues

If FCR assumptions fail, confirmation can slow down or fall back to waiting for finalized blocks. Gnosis said its bridges return to finality during Ethereum hard forks or network instability.

A fast-confirmed block can still be replaced during a chain reorganization, or reorg. In that case, the bridge-validators implementation specifies alerts rather than automatic reversal, since bridge contracts cannot un-sign transactions.

A checker compares processed source blocks with the finalized chain. Operators must arrange manual signing for legitimate messages missed on the replacement chain. The implementation does not specify who would cover a resulting loss.

Since Omnibridge mints tokens on Gnosis against assets held on Ethereum, a deposited transaction disappearing without being included again could leave corresponding tokens without backing.

No link to Ethereum Economic Zone or atomic transactions

The live bridge change is separate from the Ethereum Economic Zone framework that Gnosis and Zisk unveiled earlier this year. Gnosis's announcement described atomic transactions as a next step: an Ethereum contract would be able to call a Gnosis contract and use its return value within the same transaction, without a bridge. FCR speeds existing bridges but does not deliver that cross-chain execution capability.

What is confirmed

• Gnosis's xDAI bridge and Omnibridge now use FCR for Ethereum deposits.
• Confirmation time is about 12 seconds from Ethereum, compared to at least roughly 13 minutes under finality.
• All Ethereum transfers use FCR by default; no user or app changes are required.
• Reverse transfers still wait for Gnosis Chain finality.
• Bridge contracts are unchanged.

What is still unclear

• It is unconfirmed who would cover losses if a fast-confirmed deposit disappears during a reorg and leaves bridged tokens unbacked.
• The implementation does not specify automatic reversal procedures, leaving operator response to manual processes.

Why this matters for bridge users

Fast confirmation reduces the wait time for moving assets from Ethereum to Gnosis Chain, which could improve the experience for users and applications relying on these bridges. However, the lower confirmation time comes with different security assumptions and a fallback process that depends on bridge operators rather than on-chain enforcement.

Sources

• The Defiant