A turning point in a decade-long debate: Will Ethereum end the "impossible triangle" controversy?

Written by: imToken

You've all heard the term "impossible triangle" so many times you're sick of it, right?

In the first decade of Ethereum's existence, the "impossible triangle" was like a physical law hanging over the heads of every developer—you could choose any two of decentralization, security, and scalability, but you could never have all three at the same time.

However, looking back from the beginning of 2026, we will find that it seems to be gradually becoming a "design threshold" that can be crossed through technological evolution. As Vitalik Buterin pointed out on January 8, "Increasing bandwidth is safer and more reliable than reducing latency. With PeerDAS and ZKP, Ethereum's scalability can be increased by thousands of times, and it does not conflict with decentralization."

Will the "impossible triangle" that was once considered insurmountable really disappear in 2026 with the maturity of PeerDAS, ZK technology and account abstraction?

Why has the "impossible triangle" remained unsolved for so long?

We need to first review the concept of the "blockchain trilemma" proposed by Vitalik Buterin, which was specifically used to describe the dilemma faced by public blockchains in simultaneously achieving security, scalability, and decentralization:

• Decentralization means low barriers to entry, broad participation, and no need to trust a single entity;
• Security means that the system can remain consistent in the face of malicious acts, censorship and attacks;
• Scalability means high throughput, low latency, and a good user experience;

The problem is that these three elements often hinder each other in traditional architectures. For example, increasing throughput usually means raising the hardware threshold or introducing centralized coordination; reducing the node burden may weaken the security assumption; and adhering to extreme decentralization inevitably sacrifices performance and user experience.

It can be said that over the past 5-10 years, from the early EOS to the later Polkadot, Cosmos, and then to the extreme performance pursuers such as Solana, Sui, and Aptos, different public chains have given different answers. Some choose to sacrifice decentralization for performance, some improve efficiency through permissioned nodes or committee mechanisms, and some accept performance limitations, prioritizing resistance to censorship and freedom of verification.

However, they have in common that almost all expansion solutions can only satisfy two of the requirements at the same time, inevitably sacrificing the third requirement.

Or to put it another way, almost all solutions are caught in a tug-of-war under the logic of "monolithic blockchain"—to run fast, you need strong nodes; to have many nodes, you need to run slowly, which seems to have become a dead end.

If we temporarily set aside the debate over the merits of monolithic/modular blockchains and carefully review Ethereum's development path in 2020—from a "monolithic chain" to a multi-layered architecture centered on "rollups"—and the recent maturity of supporting technologies such as ZK (zero-knowledge proofs), we will find that:

The underlying logic of the "impossible triangle" has been gradually reconstructed over the past 5 years through the incremental progress of Ethereum's modularization.

Objectively speaking, Ethereum has decoupled the original constraints one by one through a series of engineering practices. At least in terms of engineering approach, this issue is no longer just a philosophical discussion.

II. The Engineering Solution Approach of "Divide and Conquer"

Next, we will break down these engineering details to see how Ethereum has resolved this triangular constraint by advancing multiple technical lines in parallel over the five-year empirical period from 2020 to 2025.

First, PeerDAS achieves "decoupling" from data availability, freeing up the inherent limits of scalability.

As is well known, in the blockchain trilemma, data availability is often the first constraint that determines scalability. This is because traditional blockchains require each full node to download and verify all data, which limits the scalability limit while ensuring security. This is why Celestia, a "heretical" DA solution, experienced a major surge in the last (or the one before that) cycle.

Ethereum's approach is not to make nodes more powerful, but to change how nodes verify data, with PeerDAS (Peer Data Availability Sampling) as the core solution.

Instead of requiring each node to download all block data, it verifies data availability through probabilistic sampling. Block data is split and encoded, and nodes only need to randomly sample a portion of the data. If data is concealed, the probability of sampling failure will increase rapidly, which significantly improves data throughput. However, ordinary nodes can still participate in verification, meaning that it does not sacrifice decentralization for performance, but rather significantly optimizes the cost structure used to achieve verification through mathematical and engineering design (further reading: " The Final Chapter of the DA War? Deconstructing PeerDAS to Help Ethereum Reclaim 'Data Sovereignty' ").

Moreover, Vitalik emphasized that PeerDAS is no longer just a concept in the roadmap, but a real-world system component, which means that Ethereum has taken a substantial step forward in terms of "scalability × decentralization".

Secondly, there is zkEVM, which attempts to solve the problem of "whether each node must repeat all computations" through a verification layer driven by zero-knowledge proofs.

Its core idea is to enable the Ethereum mainnet to generate and verify ZK proofs. In other words, after each block is executed, it can output a verifiable mathematical proof, allowing other nodes to confirm the correctness of the result without having to recalculate it. Specifically, zkEVM's advantages are concentrated in three aspects:

• Faster verification: Nodes do not need to replay transactions; they only need to verify zkProof to confirm the validity of a block.
• Lighter burden: Effectively reduces the computation and storage pressure on full nodes, making it easier for light nodes and cross-chain validators to participate;
• Enhanced security: Compared to the OP route, ZK's state proofs are confirmed on-chain in real time, offering greater resistance to tampering and clearer security boundaries;

Not long ago, the Ethereum Foundation (EF) officially released the L1 zkEVM real-time proof standard, marking the first time that the ZK route has been formally incorporated into the mainnet-level technical plan. In the next year, the Ethereum mainnet will gradually transition to an execution environment that supports zkEVM verification, realizing a structural shift from "re-execution" to "verification proof".

Vitalik's assessment is that zkEVM has initially reached a production-ready stage in terms of performance and functional completeness. The real challenges lie in long-term security and implementation complexity. According to the technical roadmap published by EF, the block proof latency is targeted to be controlled within 10 seconds, the size of a single zk proof is less than 300 KB, and it adopts a 128-bit security level, avoids trusted setup, and plans to allow home devices to participate in proof generation in order to lower the threshold for decentralization (further reading: " ZK Roadmap 'Dawn': Is the Roadmap to Ethereum's End Accelerating? ").

Finally, in addition to the two points mentioned above, there are also Ethereum roadmaps based on the period before 2030 (such as The Surge, The Verge, etc.), which focus on multiple dimensions such as improving throughput, reconstructing the state model, increasing the gas limit, and improving the execution layer.

These are all trial-and-error and accumulation paths that transcend the traditional triangular constraints. It is more like a long-term main line, dedicated to achieving higher blob throughput, clearer rollup division of labor, and more stable execution and settlement rhythm, thereby laying the foundation for future multi-chain collaboration and interoperability.

Importantly, these are not isolated upgrades, but are explicitly designed as modules that overlap and reinforce each other. This precisely reflects Ethereum's "engineering attitude" toward the blockchain trilemma: instead of seeking a magic solution that works like a single blockchain, it redistributes costs and risks through multi-layered architectural adjustments.

III. Vision 2030: The Final Form of Ethereum

Even so, we still need to exercise restraint. This is because elements such as "decentralization" are not static technical indicators, but rather the result of long-term evolution.

Ethereum is actually exploring the constraint boundaries of the impossible triangle step by step through engineering practice . With the changes in verification methods (from recalculation to sampling), data structures (from state expansion to state expiration), and execution models (from monolithic to modular), the original trade-offs are shifting, and we are getting infinitely closer to the endpoint of "wanting it all, wanting it all, and wanting it all".

In recent discussions, Vitalik also provided a relatively clear timeframe:

• 2026: With some improvements to the execution layer/build mechanism and the introduction of ePBS and other directions, the gas limit that does not depend on zkEVM can be increased in advance, while creating conditions for "more widely running zkEVM nodes";
• 2026–2028: Adjustments to Gas pricing, state structure, and execution load organization to enable the system to operate safely under higher loads;
• 2027–2030: As zkEVM gradually becomes an important way to verify blocks, the gas limit may be further increased, and the long-term ideal goal points to more distributed block construction;

Based on the recent roadmap update, we can glimpse three key characteristics of Ethereum before 2030, which together constitute the final solution to the Ethereum trilemma:

• The minimalist L1: L1 becomes a robust, neutral layer that is only responsible for providing data availability and settlement proofs. It no longer handles complex application logic, thus maintaining a very high level of security.
• A thriving L2 ecosystem and interoperability: Through EIL (interoperability layer) and fast confirmation rules, fragmented L2 networks are stitched together into a whole. Users are unaware of the existence of the chain and only experience a TPS of hundreds of thousands.
• Extremely low verification threshold: Due to the maturity of state handling and lightweight client technology, even mobile phones can participate in verification, which ensures that the cornerstone of decentralization is as solid as a rock.

Interestingly, just as this article was being written, Vitalik reiterated an important testing standard – the "Walkaway Test" – reiterating that Ethereum must have the ability to operate autonomously, ensuring that DApps can still function and user assets remain secure even if all server providers disappear or are attacked.

This statement actually shifts the evaluation criteria for this "end state" from speed/experience back to what Ethereum cares about most—whether the system remains trustworthy and independent of a single point of failure in the worst-case scenario.

In conclusion

People should always look at problems from a developmental perspective, especially in the rapidly evolving Web3/Crypto industry.

I also believe that many years from now, when people recall the heated debate about the impossible triangle from 2020 to 2025, they may feel that it was like people seriously discussing "how a horse-drawn carriage can simultaneously achieve speed, safety, and load-bearing capacity" before the invention of the automobile.

Ethereum's answer is not to make a painful choice among the three vertices, but to build a digital infrastructure that belongs to everyone, is extremely secure, and can support all of humanity's financial activities through PeerDAS, ZK proofs, and ingenious economic game design.

Objectively speaking, every step forward in this direction is a step onto the end of the "impossible triangle" story.