Lean Ethereum: Vitalik Buterin’s Plan for Privacy and Quantum

Vitalik Buterin has put Ethereum on a three-to-four-year clock to rebuild nearly every layer of its protocol, with the Lean Ethereum roadmap making native privacy, quantum resistance, and scalability the network’s top priorities. He posted the Lean Ethereum roadmap on July 4, 2026, alongside a draft document at the L1 strawmap document. He cast it as a reset on the scale of the 2022 Merge to proof-of-stake.

The plan arrives roughly a week and a half after the Ethereum Foundation cut its annual budget by roughly 40% and eliminated 54 roles, about 20% of its staff, the deepest restructuring in its history. “Privacy is no longer an afterthought, it is a first-class goal,” Buterin wrote. The strawmap organizes seven forks through 2029 around five north stars: a fast L1 with finality in seconds, a gigagas L1 reaching 10,000 transactions per second, a teragas L2 of 10M TPS, a post-quantum L1 with centuries-long cryptographic security through hash-based schemes, and a private L1 with shielded transfers. Critics inside and outside the foundation are already sparring over whether three to four years is too slow, too fast, or already late.

The Lean Era Begins

Buterin’s plan was posted in a thread on July 4 and elaborated in a draft document the foundation calls the strawmap, a portmanteau of “strawman” and “roadmap.” The strawmap covers forks extending through the end of the decade, on a rough cadence of one every six months, and is maintained by the EF Architecture team of Francesco, Justin, Thomas, Toni, and Buterin. The document is a living draft, not a confirmed schedule; its latest revision date is noted on the site.

The post followed a meeting of Ethereum researchers in Berlin two weeks earlier, which continued client-team discussions held in Svalbard in April. The strawmap’s north stars are concrete numbers: gigagas L1 of 1 gigagas per second (10K TPS) via zkEVMs and real-time proving, teragas L2 of 1 gigabyte per second (10M TPS) via data availability sampling, centuries-long cryptographic security through hash-based schemes for the post-quantum L1, and shielded transfers for the private L1. The plan’s three pillars (privacy, quantum resistance, and scalability) match the north stars and elevate each from a research thread to a fork-bound delivery target. The strawmap document originated at an EF workshop in January 2026, the site notes, and will get at least quarterly updates.

“Almost every major piece of the protocol will be replaced” over three to four years, Buterin wrote. The overhaul is meant to ship in pieces; the 2022 Merge arrived as a single coordinated event. Buterin has said the foundation’s technical ambitions for the strawmap remain intact despite the reduced budget.

The third major iteration of Ethereum in the same way that the Merge was the second. Almost every major piece of the protocol will be replaced over three to four years.

Vitalik Buterin, Ethereum co-founder, in his post on X. The strawmap document makes the same point in a single sentence: “an accelerationist coordination tool, sketching one reasonably coherent path among millions of possible outcomes.”

Privacy, Built Into the Protocol Layer

“Privacy is no longer an afterthought, it is a first class goal,” Buterin wrote, and the validator-level design sketched in the Extremely Lean Chain consensus design explains what that means in practice. Each validator generates a fresh pubkey every day and submits a ZK-STARK proof that updates its effective balance. The proof never reveals the previous day’s identity, so each validator identity completely re-randomizes every 24 hours; only the validator itself knows the link to its past self. Per-validator state shrinks to 1 byte of effective balance plus a 5-byte pointer to the deposit tree, down from the 48-byte pubkey Ethereum’s beacon chain stores today.

The new signature scheme is called leanWOTS and includes the pubkey inside the signature along with a Merkle proof through the deposit tree. Daily STARK proofs walk through the chain since the previous day, count participation, and update balances; a late submission does not slash, but it does block the validator from attesting until the proof lands. Slashing applies instantly to the currently active pubkey by setting effective balance to zero; slashings on previous pubkeys apply only after a day of delay. The mechanism gives Ethereum what the research post calls “fairly strong validator anonymity.” The lean client architecture lets the active validator set scale into the millions without ballooning on-chain state, the central trade-off the new design makes possible.

The Quantum Clock

Quantum safety “has shifted up a LOT in priority,” Buterin wrote, making a quantum-safe design for blobs (the temporary data layer-2 networks depend on) “urgent.” Work on quantum-safe blob designs has been underway for months. The current cryptography stack (BLS signatures, KZG commitments, and ECDSA) is exposed to sufficiently large quantum machines. The post-quantum L1 targets centuries-long cryptographic security through hash-based schemes, per the strawmap.

The strawmap names the post-quantum L1 as a top-level north star rather than a research side-track. The privacy and quantum tracks are designed in tandem: every new protocol component, from Frames to the mempool to state-tree extensions, is now evaluated by whether it can carry quantum-safe, intermediary-free privacy at low overhead. The shift mirrors the wider push across the cryptography community to retire quantum-vulnerable primitives, including the post-quantum encryption standards the U.S. National Institute of Standards and Technology finalized on August 13, 2024. The execution layer also changes: direct transaction re-execution across all nodes is replaced by recursive STARK-based verification, where one prover does the heavy computation and the rest of the nodes verify a compact proof. Buterin said recursive STARKs would become “an enshrined first-class core component of the protocol.”

Gas accounting moves toward multidimensional gas, finality decouples from the available chain, and slot times shorten over roughly the next five years. Each subsequent fork is expected to land another layer of the lean plan. The strawmap document frames the result as a post-quantum L1 capable of lasting for centuries without another foundational cryptography migration. Application developers are expected to weigh in on each piece, including the canonicalization of protocol code and the formal-verification pipeline.

The State That Scales Differently

State redesign is “probably the single most disruptive part of the plan,” Buterin wrote. Ethereum’s state, the running record of account balances and contract data, today grows as a single flexible “dynamic” structure that every node keeps. Under the strawmap, that dynamic state would continue to exist but scale only moderately. A second, more restrictive type of state is added on top, designed to scale much further without requiring block builders to sync or store all of it. The two coexist on the same chain, and an application may use either or both.

Buterin sketched a possible 2030 Ethereum holding 2 terabytes of present-day-style dynamic state alongside 100 terabytes of the new, more scalable state type. The new format suits ERC-20 tokens, NFTs, and many DeFi applications; it is not meant for “highly central” objects such as Uniswap contracts or onchain order books. No application would be required to migrate, but doing so could be “very cost-effective”: rewriting an ERC-20 token to use a new UTXO-based storage design currently under exploration could cut its transaction fees by more than 10x. Application developers, including those building privacy-focused apps, are expected to weigh in on the storage patterns before any of them become canonical.

A Leaner Foundation Behind a Leaner Protocol

The roadmap lands about a week and a half after the Ethereum Foundation announced the deepest restructuring in its history. “This year, the EF is decreasing its budget by roughly 40%, which entails some difficult decisions,” Buterin wrote in a separate post. Some 54 roles are leaving, roughly 20% of the foundation’s headcount.

The foundation’s remaining work is being organized into five clusters: protocol, access, user, community, and institutional. Treasury policy is shifting from spending an average of roughly 15% of remaining funds annually before 2026 to a target of approximately 5% after 2030. The shift turns the foundation into an endowment-style organization capable of weathering extended market downturns without short-term token sales. Severance for departing staff equals the higher of one month’s salary per year at the foundation or the legal minimum in their jurisdiction.

Senior departures have been stacking up since February, when co-executive director Tomasz Stańczak stepped down. Hsiao-Wei Wang resigned as co-executive director and board member last week, after a sabbatical. Longtime contributors Josh Stark and Trent Van Epps announced their exits in April. The foundation’s Privacy and Scaling Explorations unit, known as PSE, will wind down as a standalone group; ZK and privacy work migrates into the protocol and access clusters. Devcon, the foundation’s flagship developer conference, is expected to run smaller, cheaper, and closer to the foundation’s CROPS principles, which stand for censorship resistance, open source, privacy, and security.

The restructuring also changes how the foundation approaches one of Ethereum’s defining security philosophies: the multi-client model. Different clients are expected to focus on specialized needs, with AI-assisted formal verification taking over more of the safety net. Buterin favors what he calls a “soft lean-and-done” approach for Ethereum development. Once the strawmap is complete, the protocol would largely limit itself to security fixes and a smaller number of high-value improvements, with new features facing a much higher inclusion threshold.

The Timeline Debate

Reaction on X centered on the timeline rather than the substance. Dankrad Feist, the Ethereum Foundation researcher whose work on data sharding gave danksharding its name, called the strawmap “REALLY COOL” but said the three-to-four-year horizon “is very slow.” He argued the foundation “should be ambitious and get it done in ~1 year,” calling that “realistically possible now with LLMs.” Matt Liston, an Ethereum community developer, pushed back publicly on compressing the cadence. While a two-year delivery “seems between possible and likely,” he wrote, it “would be irresponsible” for Buterin or the foundation to communicate a one-to-two-year expectation, with “underpromising” the safer approach.

DeFi analyst Ignas captured the ambivalence in one line: “bullish for $ETH… if only the EF shipped on time.” He pointed to the Merge, which he said was “‘six months away’ for about four years,” and noted that the strawmap addresses all but one piece of market feedback: L1 reclaiming execution from layer-2 networks, privacy, quantum resistance, and faster finality. Tokenomics, he wrote, remain unaddressed, though he framed that as “a non-issue if reduced fees attract more txs/users.” The most consequential pieces of the plan, he warned, arrive in 2028 and beyond, with finality targeted for 2029, which lets competitors like Tempo and Canton compete for institutional and real-world-asset adoption in the interim.

• Dankrad Feist: one year to ship the full plan.
• Matt Liston: two years possible but irresponsible to promise externally.
• Ignas: “bullish for $ETH,” with most consequential pieces landing in 2028 and beyond.

From Berlin to 2029

The strawmap covers seven forks through 2029, on a rough cadence of one every six months. Glamsterdam and Hegotá are confirmed for the second half of 2026; after Hegotá, internally codenamed H-star, every upgrade starts to carry “a very strong Lean feel.” The fork after Hegotá, internally named I-star, marks the formal entry into the Lean era.

Glamsterdam carries two headliners: ePBS on the consensus side and BALs on the execution side. The strawmap document limits each fork to one consensus and one execution headliner to maintain the cadence. Buterin’s closing thread message said gas limit increases, blob increases, and slot-time decreases will recur over roughly the next five years, with a large gas limit increase expected alongside Glamsterdam. The foundation’s post-quantum research hub has already produced a post-quantum key registry, and at least one quantum-resistant change is being considered for Hegotá. The strawmap will get at least quarterly updates, with the latest revision date noted on the document.

Fork names follow a star-based scheme (Altair, Bellatrix, Capella, Deneb, Electra, Fulu) with incrementing first letters. Glamsterdam and Hegotá have finalized names; later forks carry placeholders like I* and J*, pronounced “I star” and “J star.” The strawmap explicitly describes itself as a draft, not a prediction, and outlines one reasonably coherent path among millions of possible outcomes. Maintainers of the document are Francesco, Justin, Thomas, Toni, and Buterin from the EF Architecture team.

• Forks planned by 2029: 7
• Cadence: one every 6 months
• L1 throughput target: 1 gigagas/sec (10K TPS)
• L2 throughput target: 1 gigabyte/sec (10M TPS)
• Post-quantum L1 target: centuries-long cryptographic security

What Remains Unproven

Once the strawmap is complete, Buterin favors a “soft lean-and-done” approach. Ethereum would largely limit protocol development to security fixes and a smaller number of high-value improvements. New features would face a much higher threshold for inclusion, making the protocol easier to maintain and harder to capture.

Buterin said Ethereum should adopt Bitcoin’s slow and conservative approach to base-protocol changes after the Lean era. That would mark a meaningful shift for a network that has historically differentiated itself from Bitcoin through rapid experimentation and an expansive roadmap. The foundation’s reorganization is the institutional complement: five domain clusters, a 5% spending target after 2030, and ZK and privacy work folded into the core protocol track. Seven forks in three-and-a-half years is a tight read, and the strawmap is explicit about its draft status. Lean Ethereum is meant to ship in pieces; each upgrade will land another layer of the plan, while the 2022 Merge arrived as a single coordinated event.

Frequently Asked Questions

What is the Lean Ethereum roadmap?

The Lean Ethereum roadmap is a multi-year protocol overhaul published by Vitalik Buterin in a post on X on July 4, 2026, alongside a draft document at strawmap.org. It targets privacy, quantum resistance, and scalability as core protocol goals across roughly seven forks through 2029. Buterin has called it the network’s third major iteration after the original proof-of-work chain and the 2022 Merge to proof-of-stake.

When does the Lean Ethereum roadmap begin?

Two forks are already confirmed for 2026: Glamsterdam and Hegotá. Hegotá, internally codenamed H-star, is “probably Ethereum’s last thematically pre-Lean fork,” Buterin wrote. The fork after Hegotá, internally named I-star, is where most future upgrades start to carry what Buterin called “a very strong Lean feel.”

What changes about validator privacy?

Under the plan, each validator generates a fresh pubkey every day and submits a ZK-STARK proof that updates its effective balance. The proof never reveals the previous day’s identity, so each validator identity completely re-randomizes every 24 hours. Per-validator state shrinks to 1 byte of effective balance plus a 5-byte pointer to the deposit tree, down from a 48-byte pubkey the beacon chain stores today.

Why is quantum resistance urgent now?

Buterin wrote that quantum safety “has shifted up a LOT in priority,” making quantum-safe blob design “urgent.” The current stack of BLS signatures, KZG commitments, and ECDSA is exposed to large quantum machines. The strawmap’s post-quantum north star targets centuries-long cryptographic security through hash-based schemes.

What is the Ethereum Foundation restructuring?

The foundation cut its annual budget by roughly 40% and eliminated 54 roles, about 20% of staff. Remaining work is organized into five clusters: protocol, access, user, community, and institutional. Treasury policy targets a ~5% annual spending rate after 2030, down from ~15% before 2026, turning the foundation into an endowment-style organization.

Disclaimer: This article is for informational purposes only and does not constitute investment, financial, or trading advice. Figures and quotes are accurate as of publication. Readers should consult a qualified professional before making any decisions related to cryptocurrency or blockchain technology.