get your heads around the math and give me feedback.
SW adds a new consensus rule: a + b/4 <= 1MB, where a is the size of the "old" block, and b is the size of the "witness" (ie, the signatures). So yes, all else being equal, this consensus rule will bias miners to select transactions with small "base" components, but with lots of signature data. Of course, transaction creators can compensate by increasing the fees for transactions with simple signatures, so it's not obvious what kinds of transactions would end up being included in blocks.
The ostensible reason for all this is twofold 1) penalize transaction that can add to the size of the Unspent Transaction Output database 2) future plans to prune off signature data for downloading historical transactions and serving transactions to SPV wallets should mean that the signature portion will theoretically consume less bandwidth in the future.
These are some of the problems I see with this new "a + b/4" consensus rule:
- It is complicated, and adds technical debt. Ironic considering this comment by GMax:
(ht
@albin )
- It is completely arbitrary. Why a 1/4 weighting? Why not 1/3, 1/6, 1/10?
- It penalizes transactions that reduce the size of the UTXO set the same as those that add to it. So it's not obvious it incentivises reducing the UTXO database.
- Changing the UTXO set is just another way of saying "updating the ledger". And as
@Justus Ranvier pointed out, ease with which one can update the ledger is one of the key properties of Bitcoin that adds to its value. So restricting changes to the UTXO set is bad for the value of the Bitcoin network.