Vitalik Buterin says that Ethereum’s “quick verification rule” can provide users with a strong guarantee that a block will not be returned after one slot, or about 12 seconds, a change that can significantly reduce the large amount of network friction through exchanges, bridges and Layer-2 systems.
The proposal, publicly described by Ethereum Foundation researcher Julian Ma and endorsed by Buterin at X, is designed to bridge the gap between Ethereum’s strong security model and the slow verification times that still shape the user experience throughout the ecosystem. In the words of Buterin, the machine “allows you to get a strong guarantee that Ethereum will not return after one slot (12 seconds). The security assumption is (i) very high reliability, (ii) network delay under ~ 3s. So one step below the last of the economy, but it is very strong for many use cases.”
Ethereum’s new rule for Fast Verification
That distinction is important. Ethereum’s ultimate is still the strongest on-chain payment guarantee, but it comes with a long waiting period. Ma said the fast confirmation rule, or FCR, reduces deposit times from the Ethereum mainnet to L2 and the average exchange to about 13 seconds, which he described as “an 80-98% reduction for most L2s and exchanges.”
For users, the immediate effect is speed. For infrastructure providers, efficiency is a big issue. Ma argued that slow mainnet verification forced exchanges, bridges and rollups to operate with delays and uncertainty, especially when handling deposits or synchronizing market activity across chains. “Combining funds from Ethereum to L2 and centralized exchanges is slow. Users wait minutes when using canonical bridges,” he wrote. “The new Fast Confirmation Rule (FCR) solves that. It reduces the time to transfer funds from Ethereum L1 to L2 or exchanges to 13 seconds.”
He added that the rule is expected to be “the new industry standard for L2 and exchanges,” and said it could start rolling out in the coming months without a hard fork. That’s a remarkable design choice. Rather than introducing a conformance change that requires network-wide communication, FCR can be activated as customers use it, with nodes able to automatically apply the rule once support is live.
Ma’s definition features FCR as a middle ground between today’s heuristics and the official end of Ethereum. Many trades, L2s and solvers are not waiting to end now. Instead, they rely on the rule of block depth, or “k-deep,” essentially waiting for a transaction to be buried under enough subsequent blocks. FCR takes a different route: it calculates proofs instead of blocks. According to Ma, that makes it structurally faster while also providing a deployable security model that lacks depth.
The trade-off is obvious. A block that is quickly verified is incomplete, and the confirmation depends on a stronger guess than the last one. FCR assumes a synchronous network, which means that the proof arrives within about eight seconds, and does not assume that the adversary controls more than 25% of the concentrated ETH. The latter, on the contrary, is designed to hold under asynchrony and up to 33% of the adversarial threshold.
However, Ma argued that the system degrades when the situation worsens. “If the network is slow, FCR has a built-in fallback mode. Instead of quickly verifying a block within 13 seconds, it may take longer,” he wrote. “As soon as enough evidence is submitted, the block is quickly confirmed. In the worst case, FCR goes back to the bottom.”
That goes back to midfield. The method does not pretend that the risk of reorg disappears; claims to dramatically reduce wait times while maintaining deterministic guarantees where its predictions remain. Ma also stressed that if those thoughts hold, the block that is quickly verified “will definitely be completed.”
At press time, ETH traded at $2,319.
The featured image was created with DALL.E, a char t from TradingView.com
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