Because of Kevaundray Wedderburn, Alex Stokes, Tim Beiko, Mary Maller, Alexander Hicks, George Kadianakis, Dankrad Feist, and Justin Drake for suggestions and evaluation.
Ethereum goes all in on ZK. Ultimately we count on emigrate to utilizing ZK proofs in any respect ranges of the stack, from consensus layer signature aggregation to onchain privateness with shopper facet proving, and improve the protocol to be easier and extra zk-friendly. However step one shall be an L1 zkEVM.
How we will ship an L1 zkEVM in lower than a yr
The quickest and most secure approach to ship an L1 zkEVM is to start out by giving validators the choice to run purchasers that, reasonably than re-executing execution payloads, statelessly confirm a number of (let’s say three) proofs generated by completely different zkVMs every proving completely different EVM implementations. As a result of proof verification is so quick and proof measurement so succinct, downloading and verifying a number of proofs may be very cheap and permits us to use the identical protection in depth as current shopper variety to zkVMs.
For this plan to initially confirm execution proofs offchain, all we want from the protocol is a few type of pipelining in Glamsterdam to permit for extra proving time.
Initially, we count on few validators to run ZK purchasers. Over time, their safety shall be demonstrated in manufacturing. With the EF additionally placing assets into formal verification, specification writing, audits, and bug bounties; we count on adoption will slowly improve.
When a supermajority of stake is comfy working ZK purchasers, we will improve the fuel restrict to a degree that will require validators working cheap {hardware} to confirm proofs as a substitute of re-executing blocks. As soon as all validators are verifying execution proofs, the identical proofs will also be utilized by an EXECUTE precompile for native zk-rollups.
Defining realtime proving for the L1
Our biggest benefit in executing this plan is the flexibility to harness the complete zkVM business in direction of making Ethereum by far the most important ZK software on this planet. Many zkVMs are already proving Ethereum blocks and efficiency breakthroughs are being introduced on a weekly foundation.
So as to keep the safety, liveness, and censorship-resistance properties of the L1 the Ethereum Basis is proposing a standardized definition of realtime proving for zkVM groups to work in direction of.
On the proof system facet, zkVMs focusing on realtime proving ought to goal for 128 bits of safety, which we contemplate the suitable long-term goal for Ethereum L1. Nevertheless, we’re prepared to just accept a minimal of 100 bits of safety within the preliminary months of deployment, to accommodate short-term engineering challenges in reaching 128 bits. Proof measurement ought to stay below 300KiB and should not depend on recursive wrappers that use trusted setups. We count on proof programs to maneuver to 128-bit safety by the point ZK purchasers are in manufacturing and to additional tighten safety necessities (e.g. concerning conjectures) as proving time decreases.
With the present slot time of 12 seconds and most time to propagate information throughout the community of ~1.5 seconds, realtime means 10 seconds or much less. We count on zkVMs to have the ability to show at the very least 99% of mainnet blocks on this window, with the tail finish (in addition to artificial DOS vectors) mitigated in future onerous forks.
So as to keep the very best ranges of liveness and censorship resistance, our definition of realtime proving goals to allow “house proving” with the concept a number of the solo stakers who presently run validators from house will opt-in to proving. Although we count on to harden censorship resistance by way of enforced transaction inclusion earlier than verifying ZK proofs is made obligatory, house proving is a vital ultimate safeguard.
Since proving within the cloud is already fairly low cost with multi-GPU spot situations, the main focus for zkVM groups focusing on realtime proving will largely be optimizing for working provers on-prem the place the specs are way more constrained. On-prem realtime proving ought to require a most capital expenditure of 100k USD (at time of writing it requires ~$80k in stake to run a validator). We count on this to come back down over time even because the fuel restrict is elevated.
Greater than {hardware} value, essentially the most vital constraint for house proving utilizing GPUs is power utilization. Most residential houses have at the very least 10kW getting into from the road and a few may have circuits supposed for electrical home equipment or charging electrical automobiles with 10kW capability. Due to this fact, realtime proving have to be doable on {hardware} working at 10kW or much less.
This brings us to our working definition of realtime proving:
- Latency: <= 10s for P99 of mainnet blocks
- On-prem CAPEX: <= 100k USD
- On-prem energy: <= 10kW
- Code: Totally open supply
- Safety: >= 128 bits
- Proof measurement: <= 300KiB with no trusted setups
The race to realtime
Between now and Devconnect Argentina, we hope to see zkVM groups proceed innovating in direction of realtime house proving, and for the main zkVMs to turn out to be future core infrastructure for Ethereum.
