tl;dr: Over the past couple of days, some L2s observed that their deployments on Sepolia did not work correctly anymore. This is because of EIP-7594 which adjustments the format for proofs. In anticipation of Fusaka, we urge all blob originators to replace their software program to create Cell Proofs as an alternative of blob proofs.
Background
One underdiscussed side of EIP-7549 (PeerDAS) is that it adjustments the format for proofs from blob proofs to cell proofs. This enables for downloading a selected a part of the blob as an alternative of the entire blob for information availability sampling.
This modification would possibly break consumer functions that ship blob transactions. Already signed transactions are nonetheless legitimate although, they simply have to recompute the cell proofs. Some purchasers (most notably go-ethereum) will do that through the RPC on eth_sendTransaction and eth_sendRawTransaction (1). This conversion from blob proofs to cell proofs takes about one second, so we encourage blob transaction originators to maneuver to cell proofs with a view to cut back overhead on the RPC stage.
Transactions which might be within the txpool on the time of the fork will likely be dropped by some implementations, whereas different implementations will convert them to cell proofs. So it could be prudent to resend your transactions with cell proofs shortly after the fork, if they aren’t being included by the chain. Some implementations permit for the distribution of blob proof transactions up to some minutes after the arduous fork on the networking layer for stability functions.
Actionable adjustments
In case you are a blob transaction originator (e.g. an L2), you must replace your transaction sending code to create cell proofs.
All main consumer libraries expose performance to create these proofs through ComputeCellsAndKZGProofs() which is on the market in all main languages (2). Utilization examples can be present in all main languages within the consumer libraries (3).
Outlook
We are going to attempt to talk these adjustments that affect customers extra clearly through the Ethereum weblog going ahead and attempt to do extra neighborhood outreach to stop customers of Ethereum from feeling blindsided by adjustments within the protocol.
We additionally encourage L2s and different entities that closely rely on the Ethereum roadmap to observe the ACD course of and to have interaction extra straight with the neighborhood. We might additionally wish to encourage groups to deploy their contracts and check infrastructure on the devnets shortly earlier than we transfer to the primary testnets.
One other useful gizmo for maintaining your adjustments updated is to make use of the Ethereum package deal offered by Kurtosis which can be utilized to create native networks with the newest specs (4).
Whereas it’s unlucky that blob originators discovered this late within the arduous fork course of, it additionally reveals that the testnet course of works very effectively and these points are caught lengthy earlier than they might ever seem on mainnet.
(1): go-ethereum will solely do the conversion on eth_sendRawTransaction from present grasp and v1.16.5 onwards
(2): see https://github.com/search?q=repo%3Aethereum%2Fc-kzg-4844%20ComputeCellsAndKZGProofs&type=code
(3) Instance for go-ethereum: https://github.com/ethereum/go-ethereum/blob/7c107c2691fa66a1da60e2b95f5946c3a3921b00/crypto/kzg4844/kzg4844_test.go#L194
(4) Ethereum package deal for kurtosis: https://github.com/ethpandaops/ethereum-package
