Ethereum is on the verge of a significant step in its scalability roadmap with the upcoming Fusaka upgrade. This enhancement, centered on a sophisticated data handling system called PeerDAS, is designed to dramatically increase network capacity and reduce costs for Layer 2 solutions, all while maintaining the network’s decentralized nature.
The Fusaka Upgrade: A New Chapter for Scalability
Scheduled for its mainnet activation on December 3, 2025, the Fusaka hard fork is a bundled set of improvements that represents one of the most substantial updates since The Merge. Unlike some previous upgrades that added user-facing features, Fusaka is largely a “behind-the-scenes” infrastructural overhaul focused on optimizing Ethereum’s core engine for the future. Its success is considered critical for the network’s long-term scalability and efficiency.
A key feature of Fusaka is its structured, multi-phase rollout, which is designed to mitigate risk. The process begins with the mainnet hard fork on December 3rd, followed by two subsequent “Blob Parameter Only (BPO)” forks on December 9, 2025, and January 7, 2026. These BPO forks are designed to dynamically increase the data capacity for Layer 2 rollups without requiring full network upgrades, making Ethereum’s scaling process more agile.
PeerDAS: The Engine of Change
The centerpiece of the Fusaka upgrade is EIP-7594, known as Peer Data Availability Sampling (PeerDAS). This innovation fundamentally changes how Ethereum nodes handle the large amounts of data posted by Layer 2 rollups.
Currently, every validator must download and store entire “blobs” of data, which is a major bottleneck as rollup usage grows. PeerDAS solves this by allowing validators to instead download and verify only small, random samples of this data. The full dataset can be cryptographically reconstructed from these samples, ensuring the data is available without burdening every single node with the full load. This is akin to checking a few items from a large shipment to verify the entire order’s quality, rather than inspecting every single box.
The impact of this change is profound. It reduces the bandwidth and storage requirements for individual validators, making it cheaper and easier to run a node. More importantly, it safely unlocks a potential 8x increase in data throughput for Layer 2 networks, allowing them to process transactions faster and more cheaply than ever before.
The Recent Gas Limit Increase
In a related and crucial move, Ethereum has already successfully increased its block gas limit. Through EIP-7935, the default gas limit has been raised from 36 million to 60 million, a significant 67% increase that directly expands the network’s base-layer transaction capacity.
This adjustment, activated automatically on November 25th after support from over half of the network’s validators, provides immediate relief by allowing more transactions per block and helping to ease upward pressure on fees during periods of high demand. It’s important to note that this is a configuration change coordinated through client teams rather than a consensus-level rule change, and it has been rigorously tested to ensure network stability.
A Wider Impact on the Ecosystem
The combined effect of the gas limit increase and the Fusaka upgrade will be felt across the entire Ethereum ecosystem.
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For Users and Developers: While the changes are largely under the hood, the downstream effect should be a smoother, cheaper experience. Users can expect more predictable gas fees, while developers will benefit from a higher gas ceiling, enabling more complex and feature-rich decentralized applications.
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For Validators and Node Operators: Features like PeerDAS and EIP-7642 (History Expiry), which allows for the pruning of old historical data, significantly lower the hardware requirements for running a node. This reduces operational costs and, crucially, helps preserve the network’s decentralization by keeping it accessible to solo stakers.
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For Security and Future Growth: The upgrade includes vital security enhancements. EIP-7825 introduces a per-transaction gas cap to prevent any single transaction from consuming an entire block, protecting the network from spam and DoS attacks. Furthermore, upgrades like EIP-7951, which adds native support for the secp256r1 elliptic curve, pave the way for seamless integration with Web2 security standards like Apple’s Secure Enclave and FIDO2/WebAuthn, enabling biometric authentication for wallets.
The Fusaka upgrade is a foundational step that strengthens Ethereum for the next wave of adoption. By significantly boosting capacity for Layer 2s and improving the overall user and validator experience, it solidifies the network’s path toward a more scalable and accessible future.
