Fusaka Update - Information for Blob users

Ethereum's upcoming Fusaka upgrade introduces a critical change: blob proofs are being replaced by cell proofs, impacting Layer 2 deployments and blob transaction workflows.

The Ethereum Foundation's blog post explains that recent issues on the Sepolia testnet stem from the implementation of EIP-7594, which shifts the proof format used in blob transactions. This change is part of the broader Fusaka upgrade and PeerDAS initiative, aimed at improving data availability sampling by allowing partial blob downloads.

What’s Changing?

Blob proofs → Cell proofs: Cell proofs enable more efficient data sampling and are now required for blob transactions.
Impact on L2s: Some Layer 2 deployments failed on Sepolia due to outdated blob proof formats.
Client behavior: Clients like go-ethereum will auto-convert blob proofs to cell proofs during transaction submission, but this adds ~1 second of overhead

Why It Matters?

The Ethereum Foundation plans to improve communication around protocol changes and encourages L2 teams to engage more actively in the ACD (AllCoreDevs) process. While the late discovery of this issue was unfortunate, it highlights the value of thorough testnet validation before mainnet rollout.