TLDR:
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- Vitalik proposes cutting Ethereum’s slot time from 12 seconds to 2 seconds using a sqrt(2) formula.
- Erasure coding upgrades to Ethereum’s p2p layer will reduce block propagation time across the network.
- The Minimmit finality algorithm targets a reduction from 16 minutes today down to just 8 seconds.
- Ethereum’s quantum-resistant upgrades will roll out in phases, with slot protection arriving first.
- Vitalik proposes cutting Ethereum’s slot time from 12 seconds to 2 seconds using a sqrt(2) formula.
Ethereum’s Fast L1 goal took center stage as Vitalik Buterin published a detailed strawman roadmap outlining how the network plans to evolve its base layer.
The document covers slot time reductions, peer-to-peer network upgrades, and a new finality algorithm. Buterin walks through each goal methodically, explaining how the changes interconnect.
The roadmap presents a phased, component-by-component transformation of Ethereum’s consensus layer toward a faster, simpler, and quantum-resistant design.
Slot Time and Network Architecture at the Core of Fast L1
Ethereum’s Fast L1 goal begins with a structured reduction of slot time across multiple incremental steps. Buterin proposes moving from the current 12 seconds down through 8, 6, 4, 3, and eventually 2 seconds per slot.
Each reduction follows a “sqrt(2) at a time” formula, with steps only taken when safety is confirmed.
Supporting shorter slots requires major improvements at the network layer. Buterin points to ongoing work by @raulvk on an optimized peer-to-peer design using erasure coding.
The new architecture splits each block into pieces so that any subset of them is enough to reconstruct the full block.
In his post, Buterin explained: “split each block into 8 pieces so that with any 4 of them you can reconstruct the full block.” This design cuts 95th percentile block propagation time and makes shorter slots viable without security tradeoffs.
That said, adding protocols like ePBS and FOCIL to the slot structure tightens timing constraints. These changes shrink the safe latency window from one-third of a slot to one-fifth.
To offset this, researchers are exploring a model where only 256 to 1,024 randomly selected attesters sign per slot, eliminating the aggregation phase and shortening slot duration further.
Finality Overhaul and the Shift to Quantum-Resistant Consensus
Beyond slot time, the strawman roadmap targets a complete rework of how Ethereum achieves finality. Today, finality takes roughly 16 minutes on average, calculated across 12-second slots, 32-slot epochs, and 2.5 epochs. Buterin wants to decouple finality from slot time entirely so each can be optimized on its own path.
The target is a one-round-finality algorithm called Minimmit, a variant of the established BFT consensus design. A projected trajectory moves from 16 minutes today through several intermediate stages, eventually reaching as low as 8 seconds with aggressive Minimmit parameters.
These changes will also carry a transition to post-quantum cryptography, including hash-based signatures and a STARK-friendly hash function.
Three hash function options are under active research: adjusting Poseidon2’s round count, returning to Poseidon1, or adopting BLAKE3 as a conventional alternative.
Buterin described the overall transformation as a “ship of Theseus” style process, replacing each part of Ethereum’s consensus layer one at a time.
Notably, the phased approach means slot-level quantum resistance could arrive well ahead of finality-level protection, providing an early security layer if quantum computing advances faster than anticipated.
