Ethereum Fast Confirmation Rule Set to Slash Deposit Times
Ethereum Foundation researcher Julian Ma has proposed a new rule called Fast Confirmation Rule (FCR) to reduce deposit times from Ethereum mainnet to Layer 2 networks and centralized exchanges. Currently, these transactions take around 13 minutes to confirm, but FCR would bring this time down to approximately 12 seconds.
The proposal was endorsed by co-founder Vitalik Buterin, who described it as providing 'a hard guarantee that Ethereum will not revert after one slot (12 seconds)'. FCR operates below Ethereum's formal finality and relies on two explicit assumptions: that the network delivers attestations within approximately 8 seconds, and that no single actor controls more than 25% of staked ETH.
If these conditions fail, FCR stalls and falls back to finalized head rather than producing an unsafe confirmation. Ma described this as degrading gracefully, with a block being fast-confirmed once sufficient validator attestations have accumulated. If the assumptions hold, a fast-confirmed block 'will be finalized with certainty', according to Ma.
The mechanism is already being worked on by consensus layer client teams and will activate via a configuration flag that queries the existing JSON-RPC safe tag. This means it will require no new API endpoints and no network-wide coordination. The rule's impact is expected to bring an '80-98% reduction' in deposit times for most L2s and exchanges, with Buterin calling it 'very strong for many use cases'. However, some developers have raised concerns that the 'supermajority honest' assumption carries significant weight and could lead to liveness issues if adversarial stake exceeds 25%.