BlockchainEthereum
|4 min ReadFusaka puts Ethereum on a bigger, faster track
Carter Hayes
Senior Analyst
Published
Jan 16, 2026
The Fusaka upgrade lands in December 2025. It is not a tune-up. It is a redesign of how Ethereum scales data, prices blobs, and keeps bad actors out. The centerpiece is PeerDAS, short for data availability sampling, and it changes the math of rollup data.
PeerDAS makes data lighter and throughput bigger
Today, every full node stores every blob that rollups post. That keeps redundancy high but creates a bottleneck as demand grows. With PeerDAS, each node stores only a slice of the data, roughly one eighth, and uses cryptographic sampling to verify that the full dataset is available. Error probabilities fall to the one-in-10²⁰ to one-in-10²⁴ range. It is rigorous. It is efficient. It aims to boost blob throughput by up to eight times without forcing node operators to buy bigger boxes or more bandwidth. Rollups get the immediate benefit because blobs are their lifeblood. The plan is clear on the roadmap, and it is a beautiful piece of engineering that keeps costs in line with growth. See the overview and PeerDAS notes on Ethereum’s roadmap at ethereum.org and PeerDAS.
Blob economics get rules, not vibes
Fusaka also cleans up blob pricing and control. Under EIP-7918, a reserve fee sets a baseline price for blobs. In the current market, blob fees can drift toward zero when execution gas dominates. That invites waste. The reserve fee forces Layer 2s to pay a fair minimum for the storage and bandwidth they use. Read the spec at EIP-7918.
Then there is EIP-7892, which lets clients adjust blob parameters without a full hard fork. Think of it as a targeted lever for blob throughput. If Layer 2 demand spikes or softens, the network can respond faster, with less coordination risk. That is how you build flexible infrastructure for a system that must scale in real time.
Hard limits for a tougher network
Scaling brings a larger attack surface, so Fusaka tightens the guardrails. EIP-7823 caps the input size for the MODEXP operation at 8192 bits to prevent oversized math from hammering clients. EIP-7883 raises gas costs for large MODEXP exponents to match true compute effort. EIP-7825 sets a per-transaction gas cap at 2²⁴ units, which stops monster transactions from crowding out the mempool. EIP-7934 caps the execution block size at 10 MB to keep block propagation healthy. The themes are simple. Cap the extremes. Price heavy work fairly. Keep blocks right-sized. See the proposals at EIP-7823, EIP-7825, EIP-7883, and EIP-7934.
New tools for users and builders
Fusaka adds speed and compatibility where it matters. For users, EIP-7917 introduces preconfirmations. Wallets can look ahead in the proposer schedule so a user can lock in that a transaction will appear in an upcoming block. That reduces latency and lowers anxiety around inclusion. See EIP-7917.
For developers, two upgrades stand out. EIP-7939 adds a CLZ opcode, count leading zeros, a handy primitive for cryptography and bit-level tricks. EIP-7951 brings native secp256r1, also known as P-256, signature verification. That curve is common in phones and hardware devices. Native support improves compatibility and strengthens account abstraction designs. Find the details at EIP-7939 and EIP-7951.
What ETH holders need to do, and when
Everyday users do not need to lift a finger. Balances, tokens, dapps keep working. Ignore any scam that tells you to “upgrade” ETH or move coins. There is no such requirement.
The work falls on validators and node operators. They must upgrade both execution and consensus clients in step. Coordination is critical. If a share of validators lags, you risk downtime or temporary chain splits. That is why the teams run testnets and dress rehearsals before the big day.
Core developers have set mainnet activation for December 3, 2025 after a clean third testnet run. The timeline is tight, the testing has been serious, and the target is locked in. Once live, the wins should be obvious. More blob capacity for rollups. Stronger DoS defenses. Better tools for wallets and contracts. A network that scales without burning out the people who run it.
Fusaka is Ethereum betting on data sampling, smarter fees, and practical limits. It is a historic move in a roadmap that has delivered The Merge, Shanghai, Dencun, and Pectra. If it lands as designed, layer-2 demand gets room to grow, node operators stay within reach, and developers get cleaner primitives. That is how you build the next chapter. That is how you keep Ethereum competitive when everyone is watching.
Disclaimer: This document is intended for informational and entertainment purposes only. The views expressed in this document are not, and should not be taken as, investment advice or recommendations. Recipients should do their own due diligence, taking into account their specific financial circumstances, investment objectives and risk tolerance, which are not considered here, before investing. This document is not an offer, or the solicitation of an offer, to buy or sell any of the assets mentioned.