Block header structure change under the Merge to Proof of Stake?

Question

The yellow paper describes the below block header structure:

This includes difficulty, beneficiary, mixHash and nonce values. Presumably these will be redundant under Proof-of-Stake. How will the Block Header structure change under proof of stake? Where is this defined? If it's to be confirmed, where/when is it likely to be confirmed.

Answer 1

Your question is a bit tricky because it depends on which types of block you speak of.

After the merge, the beacon blocks will encapsulate all the info and thus can be considered as "the main block". Their header will look like this:

class BeaconBlockHeader(Container):
  slot: Slot
  proposer_index: ValidatorIndex
  parent_root: Root
  state_root: Root
  body_root: Root

But your question seems to be focused on the execution layer type of block. And even if the block header is as I've shown above, most of the info previously in the header of execution layer will remain available. This picture gives a good overview of what will change:

(source: https://blog.ethereum.org/2021/11/29/how-the-merge-impacts-app-layer/)

The change indicated on the picture isn't the only one, as the website where this image comes from states:

Post-merge, several fields previously contained in proof of work block headers become unused as they are irrelevant to proof of stake. In order to minimize disruption to tooling and infrastructure, these fields are set to 0.

And the changes are the following:

Because proof of stake does not naturally produce ommers (a.k.a. uncle blocks) like proof of work, the list of these in each block (ommers) will be empty, and the hash of this list (ommersHash) will become the RLP-encoded hash of an empty list. Similarly, because difficulty and nonce are features of proof of work, these will be set to 0, while respecting their byte-size values. mixHash, another mining-related field, won’t be set to 0 but will instead contain the beacon chain’s RANDAO value.

Answer 2

I don't think the proof of stake makes block header structure will change at all..what happens was the way of management of blocks will improve also can make gas fee increase.. that one most important for us

Answer 3

This includes difficulty, beneficiary, mixHash and nonce values. Presumably these will be redundant under Proof-of-Stake.

Not necessary. The header (at least its structure) can be easily the same. Proof-of-Stake may only manage the block creation and confirmation (i.e. network synchronization/stabilization), without reformatting the block structure itself.

How will the Block Header structure change under proof of stake?

If you talking about Ethereum network, then only Ethereum team knows it.

Where is this defined? If it's to be confirmed, where/when is it likely to be confirmed.

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