jakiro
Ethereum will soon usher in a hard fork upgrade called “Fusaka” on December 3, 2025.This upgrade includes 12 Ethereum Improvement Proposals (EIPs), which are like 12 precision parts, and will jointly improve Ethereum’s scalability, security and operational efficiency.Next, the author classifies these 12 EIPs and interprets in popular language what problems they solve and why they are crucial to the future of Ethereum.
Expand capacity!Make Ethereum run faster and install more
This is the core theme of Fusaka upgrade.If Ethereum wants to carry the global digital economy, it must solve the problems of transaction congestion and high fees.The following EIPs are designed to achieve this goal, especially around expanding capacity, reducing costs and increasing efficiency for Layer 2.
EIP-7594: PeerDAS – Data Availability Sampling
Pain point: Since the Dencun upgrade introduced the data “Blob” to provide cheap data storage for Layer 2, a core question has followed: How to ensure that these massive data is truly available?The current approach is to require each verification node to download and verify all the blob data carried by a block.This method is still feasible when a block carries up to 9 blobs.However, if the number of blobs further increases in the future (such as 128), downloading and verifying all blobs will incur high overhead, thereby increasing the participation threshold of verification nodes and threatening the decentralization of the network.
Solution: PeerDAS (Peer Data Availability Sampling) turns the traditional “all check” into “sampling spot check”.Simply put:
-
The network slices the complete blob data.
-
Each validator does not need to download all blobs, just randomly download and check a few data fragments.
-
Then, by random checking and exchanging verification results, we can jointly confirm the integrity and availability of the entire set of blob data.
This is like a large puzzle game, where everyone has only a few pieces of fragments on their hands, but as long as everyone checks each other’s key connections, they can confirm that the entire puzzle is intact.It is worth pointing out that PeerDAS is not a brand new invention, and its core DAS ideas have been successfully practiced in third-party DA projects such as Celestia.The implementation of PeerDAS is more like making up for a key “technical debt” for Ethereum’s long-term expansion blueprint.
Significance: PeerDAS greatly reduces the storage burden of validators and clears obstacles that may weaken decentralization for Ethereum to achieve large-scale data expansion.In the future, each block is expected to accommodate hundreds of blobs to supportTeragas Vision claims up to 10 million TPS, and at the same time, ordinary people can easily run validators and keep the network decentralized.
EIP-7892: BPO hard fork – lightweight parameter upgrade
Pain point: The market demand for Layer 2 data capacity is changing rapidly. If you have to wait for a large upgrade like Fusaka every time you adjust the number of blobs, it will be too slow and cannot keep up with the pace of ecological development.
Solution: This EIP defines a special “Blob Parameter Only Hardfork (BPO) mechanism.This upgrade is very lightweight. It only modifies several parameters related to blobs (such as the number of target blobs per block) and does not involve complex code changes.Node operators don’t even need to upgrade client software, they just need to accept new parameters at a specified time, just as simple as updating a configuration file to the software online.
Significance: The BPO mechanism allows Ethereum to quickly and securely regulate network capacity.For example, after this Fusaka upgrade, the community plans to perform two consecutive BPO upgrades in a short period of time, gradually double the Blob capacity.This allows Ethereum to expand the blob space on demand, elastically and incrementally, smoothly increase the cost and throughput of L2, and the risks are more controllable.
EIP-7918: Stabilize the Blob Fee Market
Pain points: The original adjustment mechanism of blob fees was too “accompanied to the market”, which brought some unexpected problems.First, when the market demand for blobs is very low, the cost will drop to near zero, but this will not effectively stimulate new demand, but will instead create an abnormal “historical lowest price”.On the contrary, when demand is strong, blob fee will soar again, creating another extremely high price.This drastic price “inversion” has made Layer 2’s cost planning difficult.
Solution: The core idea of EIP-7918 is to no longer allow blob fees to fluctuate unlimitedly, but to set a reasonable price range for it, namely, elastic “minimum consumption”.The implementation method is to link the upper and lower limits of the blob fee to the execution fee of Layer 2 on Layer 1.Whether it is updating the status root or verifying the ZK proof once, these execution fees are relatively stable and have little to do with the transaction volume in the L2 block.Therefore, linking the upper and lower limits of the blob fee to this stable “anchor” can prevent its price from jumping up and down.
Significance: The direct benefit of this improvement is to prevent the “involving” of the Blob fee market and make the operating cost model of the Layer 2 project more predictable, so that Layer 2 can formulate more stable and reasonable transaction fees for end users, and avoid a roller coaster experience of “free today and sky-high prices tomorrow”.
EIP-7935: Improve main network transaction capacity
Pain point: The total transaction volume that each Ethereum block can accommodate is determined by the “block Gas upper limit” (currently about 30 million), and has not been adjusted for many years.The most direct way to increase the throughput of the entire network is to increase this upper limit, but it is necessary to ensure that the hardware threshold for verification nodes is not raised and the degree of decentralization is not weakened.
Solution: This proposal suggests that the block default Gas cap should be raised to a new level (the specific value is pending, which may be 45 million or higher).This is not a forced lock, but gives a new recommended default value, leading consensus layer validators to gradually accept higher Gas caps.
Meaning: This means that each Layer 1 block can package more transactions, the TPS of the Ethereum main network will be directly improved, and network congestion and soaring Gas fees can be alleviated.Of course, this also puts higher demands on the validator’s hardware, so the community will carefully test and advance.
Safety and stability!Build a solid line of defense for the network
While expanding capacity, the network must be secure and stable.The Ethereum Foundation was launched in May 2025“Trillion Dollar Security, 1TS”, the goal is to build an Ethereum network that can safely carry trillion-dollar assets.The multiple EIPs in Fusaka are just the advancement of the 1TS plan, just like installing more reliable “brakes” and “guardrails” to high-speed Ethereum.
EIP-7934: Set the upper limit of physical size of blocks
Pain point: Ethereum’s “block Gas upper limit” only cares about the total calculation amount of all transactions in the block, but does not specify the physical size of the block.This brings up a vulnerability: an attacker can carefully construct a large number of “low-cost, large-volume” transactions (such as transferring 0 ETH to a large number of addresses, with extremely low calculation amounts but large data amounts), thereby packing out a block with a calculation amount that is far from exceeding the standard but has an extremely large physical volume.This kind of “data bomb” block will spread extremely slowly on the network, which may cause some nodes to fail to receive data in time and fall behind, posing a serious risk of DoS (denial of service) attacks.
Solution: Set a hard upper limit of 10MB for each block size.Any block exceeding this volume will be rejected by the network.
Significance: This is equivalent to specifying the maximum size of trucks on the road to prevent “ultra-wide and extra-long” vehicles from affecting traffic.It ensures that blocks can propagate quickly in the network, reduces latency, improves network stability and attack resistance.
EIP-7825: Set Gas limit for single transactions
Pain point: Currently, although the block has a total Gas upper limit, there is no single transaction.In theory, someone can construct a transaction that consumes almost the entire block resource and squeeze out the transactions of everyone else, which is neither fair nor safe.
Solution: Set one for each transaction16.77 million Gashard upper limit.Complex operations exceeding this scale need to be split into multiple transactions in advance before they can be submitted.
Significance: This improves the fairness and predictability of the network, ensuring that no transaction can be “contracted”.The user’s ordinary transactions will not be excessively delayed because of a “super large order”.
EIP-7823 & EIP-7883: ModExp precompilation and security reinforcement
Pain point: ModExp is a function used in Ethereum to handle large power modulus operations, and is commonly found in some cryptography applications.But it has two risks: one is that the length of the input number has no upper limit, and it may be “exploded” by maliciously constructed super large inputs; the other is that its Gas charging standard is relatively low, and it may be called in large quantities by attackers at low cost, thereby consuming node resources.
Solution:
-
EIP-7823: Set an upper limit of 8192 bits for the input length of ModExp, which is more than enough for practical application requirements.
-
EIP-7883: Increase Gas charges for ModExp, especially for larger inputs, and the fees will increase dramatically to ensure that the calculation cost matches resource consumption.
Significance: These two improvements take a two-pronged approach, removing a potential attack vector.They are like giving a computing service a “maximum task” and adjusting the “ladder electricity price” to prevent abuse, thereby improving the robustness of the entire network.
Feature upgrade!Provide developers with more powerful tools
In addition to scaling and security, Fusaka has also brought some practical new tools and features to developers, making building applications on Ethereum more efficient and powerful.
EIP-7951: Compatible with mainstream hardware signatures
Pain points: The built-in security chips of mobile phones (such as iPhones), bank U-shields, hardware security modules, etc. generally use an encryption standard called secp256r1 (also known as P-256).Ethereum uses another standard secp256k1 by default, which makes these mainstream devices unable to directly interact with Ethereum securely, limiting the large-scale popularization of Web3.
Solution: Add a new precompiled contract to enable Ethereum to natively support and verify signatures from the secp256r1 curve.
Meaning: This is a milestone improvement.It opens the door to billions of hardware devices around the world for Ethereum.In the future, you can directly sign Ethereum transactions with the security chip in your phone, without additional wallet applications or complex conversions, and the experience is smoother and more secure.This greatly lowers the threshold for the traditional world to access Ethereum, and is a major benefit to the integration of Web2 and Web3.
EIP-7939: Added CLZ efficient calculation instruction
Pain point: In smart contracts and cryptography applications, it is often necessary to calculate how many consecutive zero bits are at the beginning of a 256-bit number (for example, in scenarios such as hashing algorithms, compression algorithms, zero-knowledge proofs, etc.).Currently, there is no direct Opcode in Ethereum EVM to support this operation, and developers can only use complex Solidity code to implement it, which is costly and inefficient.
Solution: Add an Opcode called “CLZ” (Count Leading Zeros) to the EVM to complete the calculation in one step.
Meaning: This is like providing developers with a professional tool that saves time and effort.It can significantly reduce the Gas cost of related operations, allowing applications that rely on complex mathematical calculations (especially ZK Rollups) to run cheaper and more efficiently.
Network optimization!Invisible improvements, healthier ecology
Although the last two EIPs are not strong, they are crucial to the long-term healthy operation and coordination efficiency of the network.
EIP-7642: Reduce the burden of synchronization of new nodes
Pain point: Over time, Ethereum has accumulated a huge amount of historical data.To join the network, a new node needs to download and synchronize all this data, which is time-consuming and labor-intensive, and the threshold is getting higher and higher.In addition, after Ethereum changed from The Merge to PoS consensus, some fields that were no longer needed were retained in the old transaction receipt information, resulting in redundancy.
Solution: Introduce the “historical data expiration” strategy so that new nodes can skip some overly stale data when synchronized; at the same time, simplify the format of transaction receipts and remove redundant fields that are no longer needed.In this way, new nodes can save downloading a lot of useless data when synchronizing from the Genesis block.
Significance: This improvement makes nodes run “slimming”, and each full node synchronization can reduce data transmission by about 530GB!A lower threshold means more people can run nodes, and the decentralization and robustness of the network will be enhanced.
EIP-7917: Deterministic blocking order and pre-confirmation
Pain point: To understand the importance of this EIP, we have to first talk about a core pain point of the current Layer 2 Rollup: a centralized sequencer.Currently, most Rollups rely on a single entity to receive and sort users’ L2 transactions, which gives it the power to review transactions and extract MEVs, which is contrary to the spirit of decentralization.In order to solve this problem, the community proposed the idea of Based Rollup – simply abandoning L2’s own sequencer and directly using Ethereum L1’s block Proposer to sort L2 transactions, thereby inheriting the decentralization and neutrality of L1.
However, this solution has a fatal disadvantage: slowness.Layer2 must wait for the L1 block to be launched before starting to execute transactions. The delay is very large and the experience is very poor.The only solution is to introduce a “pre-confirmation” mechanism, that is, the Gateway of L2 can obtain a promise from future L1 proposers in advance: “I promise to package the transaction you submitted onto the link, otherwise compensation will be made”, so that Layer 2 can update the status (such as account balance) in advance to reduce user waiting.However, under the current mechanism of randomly deciding the proposer, the gateway has no idea who to “negotiate” with, and there is no way to discuss reliable pre-confirmation.
Solution: EIP-7917 has modified the consensus protocol so that the order of Proposer in the future can be calculated in advance and deterministically and made public.It turns the “on-site lottery” into a “block shift table” that everyone can check and is arranged in advance.
Significance: This improvement is the key cornerstone of implementing next-generation decentralized solutions such as Based Rollup.With this “shift table”, the L2 gateway can identify the proposer of a future block in advance and negotiate with it directly to obtain a trusted pre-confirmation guaranteed by Slash fine.This allows Based Rollup to enjoy L1-level decentralization and security, while also providing users with an instant transaction experience close to the centralized Sequencer.It can be said that EIP-7917 has opened a crucial door for the Ethereum ecosystem to expand its deeper “decentralized” capacity.
Why is Fusaka upgrade coming at the right time?
This Fusaka upgrade is not only a technological iteration, but also an important strategic upgrade for Ethereum in the context of the large-scale launch of traditional finance through RWA and stablecoins.At present, Ethereum, as the main battlefield, carries more than 56% of the stablecoin supply across the entire network, and has become the core settlement layer of the global digital dollar economy.Fusaka’s goal is to prepare for the “Wall Street” level assets and transaction volume.
-
Customized chains for institutional-level Layer 2, providing unlimited expansion of “fuel”
With the entry of traditional financial institutions, we will see more and more Layer 2 “special chains” customized for specific needs (such as KYC compliance).These dedicated chains require the Ethereum mainnet to provide them with massive, cheap and secure data storage space (i.e. Data Availability).
The proposals such as EIP-7594, EIP-7892 and EIP-7918 in Fusaka are to meet this demand.Its core goal is to significantly reduce the cost of Layer 2’s data release and provide flexibility in scaling on demand.
In fact, after the Pectra upgrade, the Blob fee has been very low, so why should we continue to keep it down?Because Fusaka adopts the strategy of “sacrificing short-term fee income in exchange for larger-scale economic activities”, aiming to expand the GDP of the entire network and convert more transactions into more pledges and ETH destruction, thereby supporting the value of the entire network.
-
Moving towards “trillion dollar security” and building an indestructible financial infrastructure
For financial institutions that control trillions of assets, security is an insurmountable bottom line.The Ethereum community has also put forward the ambitious goal of “trillion dollar security”.EIP-7934, EIP-7825, EIP-7823 and EIP-7883 in Fusaka are to strengthen the city walls, clear up potential safety hazards, and move towards this goal.
In short, the main line of Fusaka upgrade is clear and firm: capacity expansion and security.Driven by the dual promotion of favorable regulatory measures and market boom, Fusaka’s upgrade is timely.It will help Ethereum seize the policy trend, consolidate its dominant position in the stablecoin and asset chain field, and further transform Ethereum from a “speculative asset” to a mainstream financial infrastructure.
Conclusion: Changes in the Deep Still Water
As an important upgrade at the end of 2025, Fusaka has quietly injected strong internal motivation into Ethereum without overwhelming market speculation.The 12 improvements it contains directly hits the three major pain points of capacity expansion, safety and efficiency.What it does is to broaden the “value highway” of Ethereum, improve its carrying capacity and reliability, and prepare for a large number of users, assets and applications in the future.
For ordinary users, these changes may be “quiet”, but their impact will be far-reaching.A stronger, more efficient and secure Ethereum will have the ability to realize those grand visions that could only be imagined in the past – whether it is a global instant settlement network or “on-chain Wall Street”.Fusaka is a solid step into this future.
