Fusaka Upgrade’s EIP-7825 Proposal Clears the Largest Engineering Barrier for the Real-Time Proofs of Ethereum by Limiting Gas Upper Limits per Transaction, Realizing L1 zkEVM and Instant Proofs from Theoretical Impossibility to Engineering Feasibility, Paving the Way for Interoperability Endgame.
(Background: BitMine Invests $110 Million and 33,000 ETH! Tom Lee Calls: ETH Has Bottomed Out)
(Additional Context: Vitalik Responds to “Prysm Client” Vulnerability: Ethereum Occasional Finality Issues Are Okay! Just Avoid Finalization Errors)

Table of Contents

• 1. Behind the Fusaka Upgrade: The Underestimated EIP-7825
• 2. L1 zkEVM: The “Trust Anchor” for Ethereum Interoperability
• 3. Fusaka & EIP-7825: Unlocking the Interoperability Roadmap
• In Conclusion

In previous articles of the Interop series, we explored the OIF (Intent Framework) and EIL (Interoperability Layer), which address standardized cross-chain intent (letting the entire network understand your goals) and execution channel issues (standardized asset transfer).

However, achieving a perfect “Single Chain Experience” involves trade-offs between speed and trust. Currently, interoperability either requires accepting slowness (e.g., Optimistic Rollup’s 7-day challenge period for finality) or sacrificing decentralization (trust assumptions in multi-sig bridges).

Breaking this “Impossible Triangle” relies on a foundational capability in the Ethereum interoperability roadmap—“Acceleration” and “Finalization” enabled by ZK technology’s “Real-Time Proofs.”

And in the ongoing Fusaka upgrade, the seemingly inconspicuous EIP-7825 is precisely removing the biggest engineering obstacle to this endgame.

1. Behind the Fusaka Upgrade: The Underestimated EIP-7825

On December 4th, Ethereum’s Fusaka upgrade was officially launched on the mainnet. Unlike the grand scale of the Dencun upgrade back then, the market spotlight was mainly on Blob scaling and PeerDAS, which further reduced L2 data costs.

Yet, beyond this noise, an unassuming proposal—EIP-7825—has been quietly clearing the biggest hurdle for Ethereum’s realization of L1 zkEVM and real-time proofs, potentially laying the groundwork for the Interop endgame.

In this Fusaka upgrade, most attention centered on scalability: Blob capacity increased 8-fold, combined with PeerDAS’s random sampling verification, making the data availability (DA) cost narrative history.

Certainly, cheaper L2 solutions are good. But for Ethereum’s long-term ZK roadmap, EIP-7825 is the true game-changer, as it sets an upper gas limit (about 17,680,000 Gas) per single transaction.

It is well known that this year, the Gas Limit of Ethereum blocks has been raised to 600 million. But even with increasing limits, theoretically, if someone is willing to pay very high Gas Prices, they can still send a “Mega-Transaction” consuming the entire 60 million Gas capacity, blocking the whole block.

This was permitted before, but EIP-7825 introduces a new restriction: regardless of block size,
the gas consumed by a single transaction cannot exceed 17,680,000 Gas.

Why impose this limit? The change does not affect ordinary users’ transfers, but for ZK Provers (proof generators), it is a matter of life and death, closely related to how ZK systems generate proofs.

For example, prior to EIP-7825, if a block contained a Mega-Transaction consuming 60 million Gas, the ZK Prover would have to process this extremely complex transaction in sequence, with no splitting or parallelization—like a single-lane highway with a slow-moving giant truck blocking all other cars (transactions).

Such a scenario directly doomed “Real-Time Proofs”—proof generation time becomes uncontrollable, possibly taking minutes or longer.

Post EIP-7825, even if future block capacity expands to 100 million Gas, each transaction is forcibly limited to 17.68 million Gas. This effectively breaks down a block into predictable, bounded, and parallelizable “small task units,” transforming Ethereum’s proof generation from a difficult “logical puzzle” into a “computational power (money) problem”:
As long as sufficient parallel computing resources are invested, these split small tasks can be processed simultaneously in a very short period, enabling ZK proofs for large blocks.

As Brevis co-founder and CEO Michael said, EIP-7825 is the most underestimated upgrade on Ethereum’s path toward 100x scalability with ZK. It makes “Real-Time Proofs” go from “theoretically impossible” to “engineering schedulable”—by solving the computational problem through parallelization, even blocks of 200 million Gas could achieve proof within seconds.
This is not only a breakthrough in ZK technology but also the physical foundation for the interoperability layer (EIL) to realize second-level cross-chain settlement.

So, although this upgrade may seem not to be the main event, it is a huge breakthrough for the ZK roadmap and Ethereum scalability in 2026.

2. L1 zkEVM: The “Trust Anchor” for Ethereum Interoperability

However, while EIP-7825 paves the way for real-time proofs by limiting individual transaction size (enabling parallelization), the other side is how Ethereum’s mainnet can utilize this capability.

This involves the most hardcore narrative in Ethereum’s roadmap—L1 zkEVM.

Long considered the “Holy Grail” for scaling Ethereum, zkEVM not only addresses performance bottlenecks but also redefines the trust mechanism of blockchains. Its core idea is to enable Ethereum mainnet to generate and verify ZK proofs.

In other words, every block on Ethereum in the future could output a verifiable mathematical proof, allowing other nodes (especially light clients and L2s) to confirm correctness without re-executing transactions—if the ability to generate ZK proofs is embedded directly into the Ethereum protocol layer (L1), proposers (block packers) can generate a ZK proof for each block, and verification nodes need only verify this small proof, not re-run all transactions.

What does this mean for interoperability?

In the context of Interop, L1 zkEVM’s significance far exceeds scaling—it is the “trust anchor” for all L2s. Because if Ethereum L1 can generate real-time proofs, then all L2s can verify final states instantly and trustlessly, creating two qualitative shifts:

• Elimination of Challenge Periods: Cross-chain confirmation time shrinks from “7 days (OP mechanism)” to “seconds (ZK mechanism).”
• Decentralized Interconnection: Cross-chain communication no longer relies on trusted third-party multi-sig bridges but trusts Ethereum’s mathematical truth.

This also provides the physical foundation for our previous discussion of EIL (Interoperability Layer)—without L1’s real-time finality, cross-L2 interoperability would always suffer from “delay.”

With the target (L1 zkEVM) established and physical constraints (EIP-7825) lifted, what are the specific tools for realization?

This leads to a subtle evolution in the ZK tech stack: from zkEVM to zkVM.

3. Fusaka & EIP-7825: Unlocking the Interoperability Roadmap

If EIP-7825 provides a “hardware environment” for ZK by limiting transaction size, then the evolution of the ZK stack is about seeking a “more efficient software architecture.” Though it might sound like a tongue-twister, this is a significant distinction, marking two stages in ZK development.

The first stage is zkEVM, often seen as the compatible or “improved” branch.

Its core logic is to emulate every instruction of the EVM, allowing developers to deploy Solidity code directly, minimizing migration costs.

In other words, zkEVM’s biggest advantage is compatibility with existing Ethereum applications, greatly reducing development effort. Developers can reuse most existing infrastructure and tools (clients, block explorers, debugging tools, etc.).

However, this reliance on compatibility also bears its limitations: because EVM was not originally designed for ZK friendliness, zkEVM proof efficiency often hits a ceiling. Proof times are much slower, carrying a heavy historical baggage.

In contrast, zkVM belongs to the revolutionary camp, building virtual machines optimized for ZK proofs (e.g., based on RISC-V or WASM), to accelerate proof times and achieve better execution speed and performance.

But this may sacrifice compatibility with many EVM features and existing tooling (like low-level debuggers). Currently, an obvious trend is that more L2 projects are shedding compatibility baggage, optimizing proof speed and costs, and exploring zkVM-based architectures.

Why is Fusaka upgrade considered a “key unlocker”?

Because, prior to EIP-7825, whether zkEVM or zkVM, giant transactions on Ethereum always caused proof generation time to explode due to task un-splittability.

Now, EIP-7825 enforces splitting transactions into predictable small units, creating a parallel environment, enabling high-efficiency architectures like zkVM to operate at maximum potential. Even complex Ethereum blocks, when processed through zkVM with parallel computing, can achieve real-time proofs.

What does this mean for interoperability?
The proliferation of zkVM, combined with EIP-7825, will drastically reduce proof generation costs. When proving cross-chain proofs becomes negligible in cost and instant in speed, traditional “bridges” will vanish, replaced by underlying universal messaging protocols.

In Closing

As repeatedly emphasized in previous Interop articles, the ultimate goal of Interop is not just asset “Cross-Chain,” but a comprehensive system-level capability—encompassing cross-chain data communication, cross-chain logical execution, user experience, security, and consensus.

From this perspective, Interop can be understood as Ethereum’s future universal protocol language. Its significance lies not only in transferring value but also in sharing logic. ZK plays a role in guaranteeing execution correctness and supporting real-time state verification, enabling cross-domain calls to be “dare to do, able to do.” Without real-time ZK, truly usable Interop UX would be difficult.

Therefore, as EIP-7825 quietly activates in Fusaka and L1 zkEVM gradually becomes reality, we are infinitely close to that endgame: execution, settlement, and proof are abstracted behind the scenes, with users unaware of the chain’s existence.

This is the Interop endgame everyone of us looks forward to.