Vitalik Buterin thinks Ethereum’s ZK proving stack is turning a corner, and wants the ecosystem to use that momentum to eliminate one of its most persistent UX roadblocks: week-long L2 withdrawals on optimistic rollups.

Fraud proof windows — a requirement for canonical bridging from rollups like Base back to Ethereum — are “simply far too long for people,” Buterin wrote in a post on X last week.

“This creates large incentives to instead use solutions with unacceptable trust assumptions (eg. multisigs/MPC) that undermine the whole point of having L2s instead of fully independent L1s,” he said.

The centrality of Ethereum mainnet as an economic link will be a key factor going forward, Buterin has suggested in a new interview published today.

“The thing that keeps the L1 relevant is where assets — even if most of the activity happens on L2s — are issued on the L1,” Buterin said, adding, “Encouraging assets to actually be issued on L1 and making it economically viable to do that…is one of these really important pieces in terms of keeping the L1 central.”

Historically, optimistic proof systems required multi-day challenge periods. Getting rid of that limitation requires a shift away from optimistic proofs, as some validity proof-based rollups already have. The technological lift is much lower today.

“ZKVMs are, like, almost production-ready this year in a way that was totally not true…even one year ago,” Buterin said.

Against that backdrop, last week’s Succinct Prover Network mainnet launch is more than just another infra story.

Succinct’s decentralized marketplace lets applications submit proof requests while independent provers compete to fulfill them, receiving payments in the new PROVE token. The network already supports more than 35 protocols and has fulfilled over five million such requests securing $4 billion in value, according to Succinct Labs.

Developers are able to access global proving power using an API call, with no custom infrastructure required. That will help commoditize proof generation, co-founder Uma Roy said, with the goal to make verifiable computation “the standard for how crypto integrates with the broader internet,” making the kind of frequent validity proofs Buterin describes more economical.

Tarun Chitra, speaking on the Succinct Labs launch stream, framed the long-term impact in terms that go beyond “faster and cheaper” L2s:

“If ETH mainnet has ZK as a first-class citizen, you’ll be able to do this type of stuff, like using your collateral on mainnet somewhere else without bridging,” Chitra said.

Buterin also outlined a path beyond the one-hour target: “In the longer term, we can solve this with aggregation: N proofs from N rollups (plus txs from privacy-protocol users) can be replaced by a single proof that proves the validity of the N proofs. This becomes economical to submit once per slot, enabling the endgame: near-instant native cross-L2 asset movement through the L1.”

If these developments become reality, the capital efficiency gains could be significant. Faster canonical exits reduce reliance on trusted bridge operators, free up liquidity for market-makers and asset issuers, and concentrate settlement activity — and ETH demand — back on the base layer.

Steven Goldfeder, co-founder of Offchain Labs building Arbitrum is less confident that a pure ZK approach is ready for prime time, however.

Despite the work to accelerate progress on validity proofs, “we haven’t reached the tipping point yet where ZK technology — particularly in the form that it’s packaged up in these full-on ZK rollups — is competitive with optimistic technology, and that’s in terms of speed cost and maturity, basically the technical parity,” Goldfeder told Blockworks.

Even so, Arbitrum’s cryptography team is top-notch and has endeavored to take a non-biased view on the competing architectures over time.

“We’ll probably integrate a more hybrid variant of zero knowledge proofs at some point,” Goldfeder said. “So rather than go all in, and say this is ZK rollup only, it’s more of an optimistic rollup that can be closed out more quickly by ZK proof.”

Over the weekend, ETH closed at its third-highest weekly close ever, and it’s now within 10% of its (non-inflation-adjusted) all-time high. Part of that bid may be macro and DAT driven, but part may also be the market starting to price in the key technical pieces falling into place: maturing ZK tech, decentralized proving capacity, and a clear path to solving interoperability and UX woes.

Get the news in your inbox. Explore Blockworks newsletters:

The Breakdown: Decoding crypto and the markets. Daily.
0xResearch: Alpha in your inbox. Think like an analyst.