The turning point after ten years of debate: Will Ethereum end the debate over the "Impossible Triangle"?

Written by: imToken

The term “Impossible Triangle,” you’ve probably heard it so many times that your ears are numb, right?

In the first decade since Ethereum’s birth, the “Impossible Triangle” has been like a physical law hanging over every developer’s head—you can choose any two among decentralization, security, and scalability, but never all three at once.

However, looking back from the beginning of 2026, it seems that this has gradually become a “design threshold” that can be crossed through technological evolution. As Vitalik Buterin pointed out on January 8th, a disruptive view: “Compared to reducing latency, increasing bandwidth is safer and more reliable. With PeerDAS and ZKP, Ethereum scalability can be increased by thousands of times, and this does not conflict with decentralization.”

So, can the once deemed insurmountable “Impossible Triangle” today, in 2026, truly dissipate as PeerDAS, ZK technology, and account abstraction mature?

1. Why has the “Impossible Triangle” long remained unbroken?

First, we need to revisit the concept of the “Blockchain Impossible Triangle” proposed by Vitalik Buterin, which was specifically used to describe the dilemma that public chains face in balancing security, scalability, and decentralization:

Decentralization means low node barriers, broad participation, and no trust in a single entity;

Security means the system can maintain consistency against malicious acts, censorship, and attacks;

Scalability means high throughput, low latency, and a good user experience;

The problem is that these three often hinder each other under traditional architectures. For example, increasing throughput usually means raising hardware requirements or introducing centralized coordination; reducing node burdens might weaken security assumptions; insisting on extreme decentralization can inevitably sacrifice performance and user experience.

In the past 5-10 years, answers have varied across different public chains—from early EOS to later Polkadot, Cosmos, and the ultra-performance-focused Solana, Sui, Aptos, etc. Some sacrifice decentralization for performance, some improve efficiency through permissioned nodes or committee mechanisms, and others accept limited performance to prioritize censorship resistance and verification freedom.

But the common point is that almost all scaling solutions can only satisfy two of the three, inevitably sacrificing the third.

Or in other words, almost all solutions are stuck in a tug-of-war under the “monolithic blockchain” logic—if you want to run fast, you need strong nodes; if you want many nodes, you have to run slower. This seems like a dead-end.

If we temporarily set aside the debate over monolithic vs. modular blockchains and carefully review Ethereum’s development path from 2020, shifting from a “monolithic chain” to a multi-layer architecture centered on Rollups, and recent maturity of supporting technologies like ZK (Zero-Knowledge Proofs), we will find:

The underlying logic of the “Impossible Triangle” has been gradually reconstructed over the past five years through Ethereum’s modular approach.

Objectively, Ethereum has decoupled the originally constrained factors through a series of engineering practices. At least in terms of engineering, this problem is no longer just philosophical discussion.

2. The engineering solution of “divide and conquer”

Next, we will dissect these engineering details, specifically how Ethereum has advanced multiple technical lines in parallel during 2020–2025 to dissolve this triangle constraint.

First, by decoupling data availability through PeerDAS, freeing the inherent limit of scalability.

As is well known, in the Impossible Triangle, data availability is often the first bottleneck for scalability because traditional blockchains require each full node to download and verify all data, which guarantees security but limits scalability. This is why solutions like Celestia, which adopt a “heretical” DA approach, have seen explosive growth.

Ethereum’s approach is not to make nodes stronger but to change how nodes verify data, with PeerDAS (Peer Data Availability Sampling) as the core idea:

It no longer requires each node to download all block data but verifies data availability through probabilistic sampling—block data is split and encoded, and nodes randomly sample parts of the data. If data is hidden, the probability of sampling failure quickly increases, significantly boosting data throughput. Normal nodes can still participate in verification, meaning this is not about sacrificing decentralization for performance but about optimizing the cost structure of verification through mathematics and engineering design (see also “Is the DA War Coming to an End? Deconstructing PeerDAS and How It Helps Ethereum Reclaim ‘Data Sovereignty’”).

Moreover, Vitalik emphasizes that PeerDAS is no longer just a conceptual roadmap but a real deployed system component, marking a substantial step forward in Ethereum’s “scalability × decentralization.”

Secondly, zkEVM aims to solve the problem of “whether each node must repeat all computations” through zero-knowledge proof-driven verification layers.

Its core idea is to enable the Ethereum mainnet to generate and verify ZK proofs. In other words, after executing each block, a verifiable mathematical proof is produced, allowing other nodes to confirm correctness without re-executing transactions. Specifically, zkEVM’s advantages include:

Faster verification: nodes do not need to re-execute transactions, only verify zkProofs;

Lighter burden: significantly reduces full node computation and storage pressure, making it easier for light nodes and cross-chain validators to participate;

Stronger security: compared to OP approach, ZK state proofs are confirmed on-chain in real-time, with higher tamper resistance and clearer security boundaries;

Recently, the Ethereum Foundation (EF) officially released the real-time proof standard for L1 zkEVM, marking the first time ZK has been formally included in the mainnet-level technical plan. Over the next year, Ethereum mainnet will gradually transition to an execution environment supporting zkEVM verification, shifting from “heavy execution” to “verification proof” structurally.

Vitalik believes zkEVM has preliminarily reached a stage suitable for production in terms of performance and functionality. The real challenges lie in long-term security and implementation complexity. According to EF’s technical roadmap, block proof latency is targeted within 10 seconds, individual zk proofs are less than 300 KB, with 128-bit security, no trusted setup, and plans to enable household devices to participate in proof generation, lowering decentralization barriers (see also “ZK Roadmap ‘Dawn’: Is Ethereum’s Finality Roadmap Accelerating?”).

Finally, besides these two, the Ethereum roadmap before 2030 (such as The Surge, The Verge, etc.) involves multiple dimensions: increasing throughput, reconstructing state models, raising Gas limits, and improving execution layers.

These are all trial-and-error and accumulation paths to overcome traditional triangle constraints. They resemble a long-term mainline, aiming for higher blob throughput, clearer Rollup division of labor, and more stable execution and settlement rhythms, laying the foundation for future multi-chain collaboration and interoperability.

Importantly, these are not isolated upgrades but deliberately designed as modules that stack and reinforce each other. This also reflects Ethereum’s “engineering attitude” toward the Impossible Triangle: not seeking a magic solution like monolithic blockchains, but readjusting costs and risks through multi-layer architecture.

3. The 2030 vision: Ethereum’s ultimate form

Even so, we must remain cautious. Because elements like “decentralization” are not static technical indicators but long-term evolutionary results.

Ethereum is gradually exploring the constraints of the Impossible Triangle through engineering practice—changes in verification methods (from re-computation to sampling), data structures (from state explosion to state expiration), and execution models (from monolithic to modular). The original trade-offs are shifting, and we are approaching that “must-have, want-to-have, and still want” endpoint.

Recently, Vitalik also provided a relatively clear timeline:

2026: With some improvements in execution layers and mechanisms, introducing directions like ePBS, the Gas limit without zkEVM dependence can be increased first, creating conditions for “more widespread zkEVM node operation”;

2026–2028: Adjustments in Gas pricing, state structure, and execution load organization to maintain security under higher loads;

2027–2030: As zkEVM gradually becomes a key method for verifying blocks, Gas limits may further increase, with the long-term goal of more distributed block construction;

Combined with recent roadmap updates, we can glimpse three key features of Ethereum before 2030, which together constitute the final answer to the Impossible Triangle:

A minimal L1: L1 becomes a stable, neutral base layer responsible only for data availability and settlement proofs, no longer handling complex application logic, thus maintaining high security;

Thriving L2 and interoperability: Through EIL (Interoperability Layer) and fast confirmation rules, fragmented L2s are stitched into a whole, with users perceiving no chain existence, only experiencing hundreds of thousands of TPS;

Extremely low verification threshold: With mature state processing and lightweight client tech, even mobile phones can participate in verification, ensuring the cornerstone of decentralization remains solid;

Interestingly, as I write this, Vitalik again emphasizes an important testing standard—the “Walkaway Test”—reaffirming that Ethereum must have autonomous operation capability. Even if all service providers disappear or are attacked, DApps can still run, and user assets remain safe.

This statement essentially shifts the evaluation of this “final form” from speed/experience back to what Ethereum cares most—whether the system remains trustworthy and independent in the worst-case scenario.

In conclusion

People should always view issues with a developmental perspective, especially in the rapidly evolving Web3/Crypto industry.

I believe that many years later, when people look back at the intense debates over the Impossible Triangle from 2020–2025, they might think it’s like discussing how to make a carriage that can simultaneously be fast, safe, and carry heavy loads before the invention of cars.

Ethereum’s answer is not to find a magic trick among the three vertices but to build a digital infrastructure that belongs to everyone, is extremely secure, and can support all human financial activities through PeerDAS, ZK proofs, and clever economic game design.

Objectively speaking, every step forward in this direction is a step closer to the end of the “Impossible Triangle” story.