Written by: Ye Huiwen
Source: Wallstreetcn
Ethereum is executing a key network upgrade today called “Fusaka,” marking another significant milestone in its ongoing scaling roadmap. This upgrade aims to further lower transaction costs for Layer-2 networks by greatly increasing data capacity and optimizing protocol efficiency, strengthening Ethereum’s position as the core of a global, high-efficiency settlement layer.
According to the plan, the Fusaka upgrade will be activated at block height 13,164,544 on December 3, 2025. This follows the Dencun and Pectra upgrades, representing a new step forward for Ethereum’s scaling journey. Kenny Lee, head of crypto at Goldman Sachs, noted that Fusaka represents the next phase of Ethereum’s scalability roadmap, with the goal of evolving the network into a settlement layer with both global impact and cost-effectiveness.
The core change in this upgrade is the introduction of “PeerDAS” (Peer Data Availability Sampling) technology. This feature aims to theoretically increase Layer-2 network data capacity by 8x, enabling higher transaction throughput and is expected to significantly reduce transaction fees for Layer-2 users.
In addition, the Fusaka upgrade introduces the “Blob-only Parameter” (BPO) fork mechanism, making future network capacity increases more flexible; optimizes Layer-1 mainnet performance through features such as storage expiry and block control; and improves wallet functionality and user experience. Together, these changes constitute a structural leap for Ethereum in scalability, sustainability, and usability.
From Dencun to Fusaka: Focus on Scaling and Infrastructure Optimization
The Fusaka upgrade essentially synchronizes the consensus layer “Fulu” upgrade and the execution layer “Osaka” upgrade. According to the final plan confirmed by the Ethereum Foundation, the Ethereum Improvement Proposals (EIPs) included in the upgrade focus on three main areas:
Improving Layer-1 efficiency: Including storage expiry (EIP-7642) and transaction gas limits (EIP-7825), aimed at maintaining node efficiency as network usage grows.
Expanding Layer-2 data capacity: Centered on PeerDAS (EIP-7594), supplemented by Blob parameter updates (EIP-7892) and Blob fee optimization (EIP-7918).
Enhancing user experience and developer tools: Covering deterministic proposer preview (EIP-7917) and precompile support for the secp256r1 curve (EIP-7951), to enhance wallet functionality and application development.
These three directions are fully aligned with the Ethereum Foundation’s strategic priorities established in April 2025: scaling the Ethereum mainnet, scaling Blobs, and improving user experience. This article will focus on the increase in Layer-2 data capacity and optimization of the fee mechanism.
Core Mission: L2-Centric Scaling
To understand why Ethereum focuses on scaling through Layer-2, we need to revisit its design philosophy.
Within the “blockchain trilemma” (the inability to simultaneously achieve decentralization, security, and scalability), Ethereum’s early design prioritized decentralization and security at its base (Layer-1). As demand for decentralized applications grew, this led to bottlenecks of high transaction fees and slow confirmation times on Layer-1.
To address this, Ethereum adopted a “rollup-centric” roadmap. This strategy shifts most transaction processing to Layer-2 networks. Layer-2 executes transactions off-chain and then publishes compressed data back to Ethereum Layer-1 for final settlement and security assurance.
This modular approach allows Ethereum to scale without sacrificing its core decentralization principles. However, it introduces a new “data availability” challenge—how to prove to the entire network that published compressed data is valid, without requiring every node to download all the data.
PeerDAS: The Key to 8x Data Capacity Growth
The most influential feature in the Fusaka upgrade, PeerDAS, is designed to solve the aforementioned data availability challenge.
Before Fusaka, although the Dencun upgrade introduced “Blobs” as a cost-effective way to store Layer-2 data, every Ethereum full node still needed to download the entire Blob data, limiting network bandwidth and throughput.
PeerDAS fundamentally changes this model. After the upgrade, the network splits Blob data into small chunks and distributes them across different nodes. Each node only needs to download and verify a small portion of the total data (about 1/8), using cryptographic methods to ensure the overall data set’s availability and integrity. This greatly reduces individual node resource requirements, resulting in a theoretical 8x increase in data capacity for the network. PeerDAS lays the foundation for subsequent Blob expansion and is a key driver of lower Layer-2 transaction costs.
BPO Fork: More Flexible Blob Limit Increases
As Layer-2 transaction activity continues to grow (( Figure 2), so does demand for Blob space.
According to Coinmetrics data, daily Blob counts are on an upward trend. However, under the current mechanism, increasing the number of Blobs per block requires a complex “hard fork,” which is difficult to coordinate and infrequent.
To address this, Fusaka introduces the “Blob-only Parameter” (BPO) fork mechanism. This is a lightweight, specialized fork used solely to update Blob-related parameters (such as the maximum number of Blobs per block). Its small scope and manageable impact allow development teams to deploy such upgrades more frequently and safely, enabling the network to gradually increase data capacity without waiting for major upgrades that include other features. According to the Ethereum Foundation, BPO forks will be pre-programmed to double Blob numbers in stages over several weeks until reaching the maximum.
Stable Fee Market: Introducing the Blob Floor Price Mechanism
After the Dencun upgrade, Layer-2s publishing data to Ethereum face two separate fees: execution gas and Blob gas. When Blob demand is low, Blob fees can fall to near zero, but Layer-2s may still pay significant execution gas. This “price signal malfunction” leads to inefficient pricing and a volatile market.
To address this, Fusaka introduces a Blob “floor price” mechanism via EIP-7918. This floor price is not fixed, but dynamically linked to execution gas fees.
When market-driven Blob fees fall below this floor, the fee adjustment algorithm prevents further decreases. This ensures Blob fees always reflect their economic value, keeps the fee market sensitive to network congestion, and provides Layer-2s with a more stable and predictable pricing environment.
Market Impact and Potential Risks
The Fusaka upgrade is expected to have a profound market impact. The increased data capacity brought by PeerDAS and BPO forks is likely to further reduce Layer-2 operating costs. Meanwhile, the EIP-7918 floor price mechanism ensures Blob space cannot be used unreasonably cheaply, maintaining the network’s economic sustainability. This could intensify competition among Layer-2 networks, with the focus potentially shifting from transaction costs to user experience, ecosystem collaboration, and liquidity depth.
However, the upgrade also comes with several risks and considerations:
Execution risk: Any major hard fork carries risks of client coordination failure or vulnerabilities, potentially causing temporary network instability.
Limited mainnet fee impact: The immediate benefits of the upgrade are mainly for Layer-2s; Ethereum mainnet gas fees may not decrease right away.
Hardware requirements: While PeerDAS improves efficiency, higher Blob targets may still increase validator bandwidth needs over time.
Ecosystem adaptation lag: Layer-2 and dApp developers will need time to fully leverage the advantages of the new architecture.
