Ethereum's Fusaka Upgrade Advances with Sepolia Testnet Activation

According to Cointelegraph, Ethereum's Fusaka upgrade has been successfully activated on the Sepolia testnet, marking a significant advancement in the network's efforts to enhance scalability and performance. This upgrade represents the second phase of a three-step rollout under Ethereum's Fusaka roadmap, following the Holesky testnet activation on October 1. The Sepolia deployment is primarily focused on stress testing the network's new data-availability system and increasing the block gas limit before the final Hoodi testnet activation later this month. The Fusaka rollout introduces a range of performance and consensus improvements, aiming to increase Ethereum's block gas limit to 60 million. This enhancement allows for more transactions and complex smart-contract activities to be processed within each block, while also testing the stability of nodes at higher capacities. Gabriel Trintinalia, a protocol engineer at Consensys' client Besu and a core developer on the upgrade, highlighted the engineering efforts to ensure that current node setups can reliably handle 60 million gas blocks without risking network instability. A key component being tested is Peer Data Availability Sampling (PeerDAS), which enables Ethereum validators to verify transaction data by sampling small pieces from multiple peers instead of downloading everything. This approach improves speed and scalability while maintaining decentralization. Paul Harris, another Fusaka core developer and protocol engineer at Consensys' Teku client, noted that PeerDAS significantly reduces the burden on nodes by eliminating the need for validators to store all network data. The Ethereum Foundation announced the Fusaka testnet schedule on September 26, outlining the final steps before the network's next major upgrade. Fusaka follows this year's Pectra update, with its final trial on the Hoodi testnet set for October 28 and a mainnet launch anticipated in December. Since its inception in July 2015, the Ethereum network has undergone several major upgrades to enhance scalability, security, and performance. The most recent, the Pectra upgrade, went live on May 7, introducing key improvements such as enabling externally owned accounts to function like smart contracts and raising the validator staking cap. Prior to Pectra, the Dencun upgrade in March 2024 significantly reduced gas fees, with average fees dropping by up to 95% within a year. The Merge in September 2022 transitioned Ethereum to a proof-of-stake blockchain, ending mining and introducing validators, which reduced energy costs by up to 99%. The Shanghai upgrade in April 2023 allowed validators to withdraw staked Ether, completing Ethereum's transition to proof-of-stake.