What fields of a transaction are used when creating a transaction hash?

Question

What fields does Ethereum use when creating a hash for a transaction? Suppose the following:

1. The blockchain has three blocks block0 <- block1 <- block2
2. There's a transaction transaction2 which is originally in block2 with hash transactionHash2
3. The blockchain gets reorged such that it's now block0 <- block3 <- block4
4. transaction2 is now in block4

Would we expect that transaction2 has the same hash now that it's in a different block with a different parent block?

Answer 1

What fields does Ethereum use when creating a hash for a transaction?

There are a few transaction types supported by the network, therefore the fields needed to sign, serialize, and then generate the transaction hash vary.

Below are links to the go-ethereum repository where the different transaction types are defined (with their requisite fields/components):

• LegacyTx
• AccessListTx
• DynamicFeeTx

Would we expect that transaction2 has the same hash now that it's in a different block with a different parent block?

Yes. The block a transaction is included in is independent of the transaction object itself. Before even submitting your signed transaction to the network, you can generate your transaction hash (the hash is a fingerprint of the transaction data).