Ethereum News Today: Ethereum's Fusaka Upgrade Solves Scalability Without Sacrificing Decentralization

Ethereum's Fusaka upgrade, set to activate on mainnet in late 2025, introduces a suite of technical enhancements aimed at reducing node operational costs and enhancing scalability. The upgrade, which follows the May 2025 Pectra upgrade, incorporates 12 Ethereum Improvement Proposals (EIPs), with Peer Data Availability Sampling (PeerDAS) as its cornerstone. PeerDAS allows nodes to verify data availability through sampling rather than downloading full data blobs, significantly lowering bandwidth and storage requirements. This innovation enables Ethereum to scale blob throughput to 128 per block, supporting cheaper Layer 2 (L2) transactions while maintaining decentralization Fusaka Testnet Announcement | Ethereum Foundation Blog^[1].

The upgrade also includes Blob Parameter Only (BPO) forks, which incrementally adjust blob targets and maximums post-activation. For instance, BPO1 raises per-block blob targets from 6 to 10 and maximums from 9 to 15, with further increases in BPO2 to 14 and 21, respectively Fusaka Testnet Announcement | Ethereum Foundation Blog^[1]. These adjustments provide flexibility for L2 rollups to adapt to growing data demands without requiring major hard forks. Additionally, the gas limit on Ethereum's base layer is increased from 45 million to 60 million, enabling more transactions per block while maintaining network stability Fusaka Testnet Announcement | Ethereum Foundation Blog^[1].

Fusaka's optimizations extend to node resilience and security. EIP-7825 introduces a transaction gas limit cap of 16.7 million, preventing individual transactions from overwhelming block capacity and mitigating denial-of-service (DoS) risks. Similarly, EIP-7823 sets upper bounds for modular exponentiation operations, ensuring cryptographic computations are priced to reflect their actual computational costs Fusaka Testnet Announcement | Ethereum Foundation Blog^[1]. These changes collectively harden the network against spam attacks and resource exhaustion scenarios.

For node operators, the upgrade reduces the burden of running full nodes. PeerDAS allows nodes to store only 1/8th of the data required previously, making it feasible for operators with limited resources to participate. This shift aligns with Ethereum's goal of preserving decentralization by lowering entry barriers for smaller validators Fusaka Testnet Announcement | Ethereum Foundation Blog^[1]. Institutions with large node fleets, however, may see fewer cost savings, as their infrastructure is already optimized for high throughput Ethereum’s Fusaka Upgrade Could Cut Node Costs, Ease Adoption^[2].

The upgrade's impact on L2 rollups is expected to be profound. By enabling higher blob throughput and reducing data availability costs, Fusaka supports further declines in L2 transaction fees. VanEck, a major asset manager, highlights that PeerDAS reduces bandwidth and storage demands for validators, indirectly lowering infrastructure costs for entities operating full nodes or clusters Ethereum’s Fusaka Upgrade Could Cut Node Costs, Ease Adoption^[2]. This, in turn, reinforces Ethereum's role as a secure base layer for L2 activity, as more transactions shift to rollups without compromising L1's security guarantees Ethereum’s Fusaka Upgrade Could Cut Node Costs, Ease Adoption^[2].

Fusaka's activation follows a rigorous testnet phase. The upgrade was deployed on Holesky (October 1, 2025), Sepolia (October 14, 2025), and Hoodi (October 28, 2025), with BPO forks scheduled to follow in subsequent weeks. Client teams, including Besu, Erigon, and Lodestar, have released compatible versions for testnets, with mainnet activation pending final testing Fusaka Testnet Announcement | Ethereum Foundation Blog^[1]. Ethereum Foundation co-executive director Tomasz Stańczak emphasized the urgency of finalizing Fusaka's timeline, warning that delays could jeopardize the broader roadmap, including the planned Glamsterdam upgrade in early 2026 Fulu-Osaka (Fusaka) | ethereum.org^[11].

Developers and researchers are also preparing for post-upgrade challenges. A four-week bug bounty program, offering up to $2 million in rewards, was launched to identify vulnerabilities in the codebase before mainnet activation Ethereum Fusaka Upgrade: All You Need to Know - Binance …^[4]. This proactive approach underscores the community's commitment to security, particularly as the network's complexity increases with each upgrade.

The Fusaka upgrade positions Ethereum to address current scalability bottlenecks while laying the groundwork for future advancements, such as Verkle Trees and stateless clients. By balancing performance improvements with decentralization, the upgrade reinforces Ethereum's role as a foundational layer for Web3, ensuring it remains competitive in a rapidly evolving blockchain ecosystem Ethereum’s Fusaka upgrade takes priority as deadlines …^[6].