Ethereum’s highly anticipated Fusaka upgrade is set to go live on December 3, marking a significant development phase for the network. This upgrade features numerous enhancements aimed at optimizing rollup throughput, refining gas marketplaces, and introducing native support for passkey-style signatures.
The Fusaka fork will implement PeerDAS, a data-availability sampling approach, elevate the default block gas limit, and lay the groundwork for forthcoming blob-only parameter expansions planned for later in December and January.
Taking its name from the Fulu star (‘auxiliary road’) and the city of Osaka (‘slope or hill’), Fusaka maintains Ethereum’s longstanding tradition of combining a celestial body with a geographical location.
Editor’s Note: The term ‘slope or hill’ whimsically reflects the fusion of Fulu and Osaka, rather than serving as an official translation.
Enhanced Data Availability Through a New Scaling Layer
A noteworthy technical upgrade comes in the form of PeerDAS, detailed in EIP-7694. This protocol enables nodes to confirm the existence of blob data by sampling smaller segments, eliminating the need to download entire blobs.
This advancement removes a significant scaling bottleneck present since EIP-4844, creating a pathway to potentially increase blob throughput by approximately tenfold over time.
As blob capacity rises, this directly translates to lower transaction fees for layer-two solutions, as rollups compile user transactions into blobs that are then posted to Ethereum’s base layer.
The Fusaka upgrade will also double the default gas limit per block to 60 million gas, up from the previous limit of 30 million set after the Merge, thereby allowing for an expanded capacity for standard transactions and blob processing alike.
Furthermore, two subsequent “Blob Parameter Only” forks—BPO1 on December 9 and BPO2 on January 7—will refine blob parameters without necessitating additional code alterations, further amplifying capacity.
Reinventing the Blob Fee Market
EIP-7918 introduces a framework where the minimum blob base fee is tethered to execution gas rates, ensuring that blob prices will not plummet to negligible amounts while layer-one gas remains elevated.
This adjustment preserves the economic integrity of the data-availability market as it responds to varying usage rates. Previously, a significant disparity between blob and execution costs had created opportunities for arbitrage, distorting the economics surrounding rollups.
Additionally, several related Ethereum Improvement Proposals (EIPs)—namely 7823, 7825, 7883, and 7934—harden numerous heavy opcodes and transaction thresholds. These proposals place limits on ModExp precompile input sizes, inflate its gas costs, introduce a ceiling for transaction gas limits, and implement an RLP block size cap. Such measures are geared towards mitigating denial-of-service attack risks and making workload demands on clients more predictable.
Tools for Developers and Cryptographic Enhancements
EIP-7939 introduces a count-leading-zeros opcode, simplifying and reducing costs for bit-manipulation, integer logarithms, and randomness functions on-chain. This enhancement particularly benefits DeFi protocols and cryptographic contracts reliant on efficient bitwise operations.
The deterministic proposer lookahead specified in EIP-7917 gives validators a structured timeline detailing who will propose the next block. This allows MEV relays and staking operators to coordinate more effectively and safely, reducing the uncertainties that can complicate block production.
Moreover, EIP-7951 introduces a native precompile for the secp256r1 curve, matching the cryptographic standard utilized by Apple Secure Enclave, Android Keystore, and WebAuthn. This advancement enables wallets and smart account configurations to natively verify passkey-style signatures on Ethereum, facilitating FaceID and TouchID authentication processes without the need for custom bridges or circuits, thus decreasing friction in consumer-facing applications leveraging biometric technology.
An Immediate and Phased Rollout
The Fusaka upgrade will activate at block height on December 3, with the first blob-parameter adjustment occurring just six days after. The second adjustment, BPO2, is set for January 7, finalizing the initial capacity expansions.
This phased approach allows node operators and rollup developers to track blob usage and client performance prior to implementing further parameter modifications.
Importantly, the upgrade will not alter the consensus-layer incentives for staking or validators. All adjustments will focus on enhancing execution-layer throughput, refining gas mechanics, and evolving developer capabilities.
With its focus on maximizing throughput, Fusaka marks Ethereum’s most significant upgrade since EIP-4844 introduced blobs back in March 2024. This fork promises to double block gas capacity, enhance data-availability sampling, and incorporate cryptographic integrations for mainstream authentication hardware.
The comprehensive changes position Ethereum to accommodate heightened rollup activity without proportionally increasing fees while also providing developers with novel tools for on-chain computation and improved user onboarding strategies.
