Shaping Fusaka: Nethermind’s 6 EIPs for Ethereum’s Next Upgrade
Ethereum
•
October 14, 2025
Shaping Fusaka: Nethermind’s 6 EIPs for Ethereum’s Next Upgrade
Ethereum
•
October 14, 2025
Intro
Ethereum is about to take an important step forward in scale and performance. Scheduled for early December 2025, the Fusaka upgrade will expand Ethereum’s capacity at every layer: throughput on Layer 1, capacity for Layer 2 rollups, and a smoother experience for applications and validators.
Ethereum upgrades do not happen on their own, instead evolving through its clients. Nethermind implements Fusaka at the execution layer, enforcing protocol changes and keeping the network stable and secure in production for validators, enterprises, and developers.
Fusaka EIPs Co-authored by Nethermind Engineers
Nethermind doesn't just implement Fusaka - its engineers shaped it at the specification level. The team authored and co-authored key EIPs that define the upgrade, from gas cost recalibration to execution-layer limits and proposer logic, ensuring Fusaka's changes are grounded in real-world client experience.
Fusaka prepares Ethereum’s base layer for higher throughput
Fusaka strengthens Ethereum’s base layer, making higher throughput possible while keeping the network stable.
EIP-7642 (eth/69 - history expiry and simpler receipts): By removing the bloom filter from receipts in the networking protocol, this change eliminates roughly 530GB of unnecessary bandwidth during each node sync. Previously, serving nodes regenerated bloom filters for billions of transactions only for syncing peers to verify and discard them. The proposal also introduces a history serving window, allowing nodes to advertise which block ranges they store, making the network more efficient as Ethereum transitions toward history expiry.
EIP-7823 and EIP-7883 (Modexp worst cases): By capping parameters and adjusting gas costs for the Modexp precompile (a built-in function for modular exponentiation used in cryptographic operations), these changes close potential attack vectors and ensure pricing better reflects resource usage. This lays the groundwork for future increases to the block gas limit.
EIP-7934 and EIP-7935 (Block size and gas limit): These proposals provide coordinated limits on max block data size and max per transaction gas usage, ensuring growth in L1 throughput happens safely and predictably.
EIP-7939 (CLZ opcode): This introduces a new opcode that counts the number of leading zero bits in a 256-bit word or log2, providing a fundamental building block for mathematical operations, compression algorithms, and data structures. The native opcode makes compute cheaper, reduces bytecode size, and dramatically lowers ZK proving costs. Current Solidity implementations rely on expensive bitwise shifts that cost 1.6x more than multiplication to prove in zkVMs, making this a substantial efficiency gain for developers building on Ethereum.
These changes secure the execution layer while opening the door for safer expansion.
Fusaka expands blob capacity to lower per-transaction costs and speed up rollups
Ethereum’s rollup-centric roadmap depends on more efficient ways to handle rollup data. Fusaka delivers this with new tools that make rollups cheaper, faster, and more flexible.
EIP-7594 PeerDAS (Peer Data Availability Sampling): PeerDAS makes it possible to include more rollup data, known as blobs, without requiring each node to store all of it. This means more capacity for rollups, cheaper L2 transactions, and reduced bandwidth requirements for operators.
EIP-7892 (Blob parameter-only forks): This introduces the ability to adjust the number of blobs per block without waiting for another major upgrade. It gives Ethereum flexibility to scale more quickly in response to network conditions.
EIP-7918 (Blob base fee bound): By setting a minimum blob fee, this proposal prevents the market from collapsing to zero, resulting in healthier fee dynamics and reinforcing Ethereum’s economic security.
These EIPs make rollups more cost-effective and ensure the system can scale sustainably.
Fusaka improves predictability and consistency for users, developers and validators
Fusaka also improves how users and applications interact with Ethereum, focusing on security, predictability, and performance.
EIP-7825 (Congestion resistance): By capping transaction size, this change reduces the risk of congestion, ensures consistent network performance and allows for predicable transaction parallelisation.
EIP-7917 (Deterministic proposer lookahead): By making the block proposer schedule known in advance, this proposal speeds up confirmations and creates a more predictable environment for applications.
These proposals improve Ethereum’s resilience and create a faster, more reliable experience for both developers and end users.
What Fusaka Means for Ethereum
Fusaka is a pivotal step in scaling Ethereum across every layer:
L1 throughput: Modexp fixes and coordinated gas limit changes support safer growth.
L2 economics: PeerDAS and blob-related proposals expand capacity and stabilize fees.
UX and reliability: Congestion resistance and proposer lookahead improve stability and predictability.
The Nethermind node is ready for Fusaka. Testing is underway across devnets and testnets, with the production release scheduled ahead of the December mainnet activation. By implementing these upgrades with a focus on robustness and reliability, Nethermind enables Ethereum's scaling journey for enterprises, validators, developers, and end users.
Ethereum’s future depends on its execution clients. With Fusaka, the Nethermind node continues its track record of delivering upgrades in production, keeping Ethereum secure, scalable, and future-ready.
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