Fusaka upgrade in 1 month: Ethereum's boldest scaling gamble to date

Fusaka upgrade is expected to increase Ethereum’s data capacity by 8 times, while also enhancing DoS defense capabilities and launching new developer tools. This article is based on an article by Jason Nelson, organized, translated, and written by Foresight News. (Background: Ethereum finalized the December 3rd Fusaka hard fork upgrade, introducing PeerDAS, increasing the Gas limit) (Additional background: Ethereum launched the final testnet Hoodi, with the Fusaka upgrade scheduled to activate as early as December 3rd) Summary: Ethereum will undergo the Fusaka upgrade in December 2025, bringing data scalability, DoS attack resistance, and new developer tools. PeerDAS: Sampling Instead of Full Data Storage The core feature of the Fusaka upgrade is PeerDAS, a new way to handle blobs. In Ethereum, blobs are temporary data packets introduced with the Danksharding prototype during the Dencun upgrade. They allow rollups to submit large amounts of transaction data to the mainnet at low cost, improving scalability without permanently increasing the blockchain state. This ensures redundancy, but as demand grows, it can cause bottlenecks. Currently, every full node in Ethereum must store all blobs submitted to the chain. PeerDAS changes this logic. Each node only needs to store about one-eighth of the blobs and relies on cryptographic reconstruction techniques to fill in missing data fragments. This design uses random sampling to verify data availability with an extremely low error probability, ranging from 10^-20 to 10^-24. Through this distributed storage approach, Ethereum can theoretically increase blob throughput by 8 times without requiring node operators to upgrade hardware or bandwidth. Rollups that publish compressed transaction data via blobs are expected to be the primary beneficiaries. Blob Economics and Flexibility Fusaka also reshapes blob pricing and management mechanisms. A key adjustment is EIP-7918, which introduces a minimum reserve fee for blobs. Under current rules, when execution layer gas fees dominate, blob prices can approach zero, leading to inefficient usage. The minimum reserve fee ensures that blob usage always has a baseline cost, forcing Layer 2 to pay for its storage and bandwidth consumption. Another mechanism is EIP-7892, which introduces a fork that adjusts only blob parameters. This allows Ethereum clients to modify blob throughput without a full hard fork, enabling developers to respond flexibly to unpredictable Layer 2 demands without waiting for the next planned upgrade. Strengthening Attack Defenses Scalability also expands Ethereum’s attack surface. The Fusaka upgrade includes a series of adjustments to limit extreme cases and protect the network from DoS attacks: EIP-7823: Limits the input size of the MODEXP operation to 8192 bits; EIP-7825: Sets a gas cap of 2^24 units per transaction; EIP-7883: Increases the gas cost for large exponents in MODEXP to better match computational workload; EIP-7934: Limits execution layer block size to 10MB. These adjustments collectively reduce the risk of client overload, propagation stalls, or network instability caused by extreme transactions or oversized blocks. New Tools for Users and Developers Fusaka also aims to improve usability. For users, EIP-7917 introduces pre-confirmation support, allowing wallets and applications to preview validator proposal schedules, enabling users to lock in transaction inclusion certainty, reducing delays and confirmation uncertainty. For developers, Fusaka adds two important features: CLZ opcode, for cryptographic algorithm and contract optimization; EIP-7951, providing native secp256r1 P-256 signature verification. This elliptic curve is commonly used in hardware devices and mobile systems, and its inclusion will improve compatibility and account abstraction capabilities. These adjustments aim to lower the barrier for application developers, paving the way for new wallet designs and security models. Important Information for ETH Holders For ordinary Ethereum users, no action is required for the Fusaka upgrade. Account balances, tokens, and applications will continue to operate normally. The Ethereum official website emphasizes that users should beware of scams requesting ETH upgrades or transfers; the upgrade does not require such actions. The responsibility mainly falls on validators and node operators, who must synchronize the upgrade of execution layer and consensus layer clients. Coordination is crucial: if validators do not upgrade synchronously, the network could face downtime or temporary forks. After a series of successful testnet launches, the Fusaka upgrade is scheduled to activate on the Ethereum mainnet on December 3, 2025. Future of Ethereum Post-Fusaka The Fusaka upgrade is one of the boldest moves in Ethereum’s roadmap since the Merge. It aims to simultaneously achieve three major goals through a coordinated release: increasing blob capacity, strengthening defenses, and updating developer tools. Testing and development are ongoing, with client teams focusing on PeerDAS performance, blob pricing models, and compatibility between execution and consensus layer software. If successful, Fusaka could become a turning point for Ethereum to handle the next wave of Layer 2 adoption and scalability improvements. Related Reports: Ethereum Fusaka upgrade completed Sepoli…