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418 sats \ 6 replies \ @Scoresby OP 7 Aug \ parent \ on: Embed *entire directories* of arbitrary data contiguously in BIP110 valid blocks bitcoin

There is definitely a weakness in embedding arbitrary data

If we believe this to be true (and I do), what do you think is a reasonable response?

There have been many proposals over the last few years, and I feel that most of them have failed to be better than paying higher fees. Yes, this will lead to small utxos being priced out, but it seems to me that we are very far from that being a consistent state. And with things like taproot addresses, I wouldn't be surprised if a 1m sat utxo is pretty much always economically viable (I recognize that 1m sats is still quite a lot of money, but in the world where things less than that start to look too expensive, I doubt there will be very much spam at all on the chain).

If we are worried about the cost to noderunners, I believe the blocksize limit is a very safe control there.

228 sats \ 3 replies \ @Filiprogrammer 8 Aug

There is definitely a weakness in embedding arbitrary data
If we believe this to be true (and I do), what do you think is a reasonable response?

Activate Cross-Input Signature Aggregation and remove the witness discount.

11 sats \ 2 replies \ @optimism 8 Aug

Can you remove the witness discount without ignoring incentive formed by having 2 separate limits? I challenged the "witness discount has to be a fork" for a while and I got challenged right back and couldn't find a way to do it without underutilizing available blockspace (i.e. requiring non-profit-maxxing mining).

CISA is awesome conceptually.

244 sats \ 1 reply \ @Filiprogrammer 8 Aug

Removing the witness discount does not hurt miner incentives.
They were mining 1000000 vBytes before, they will be mining 1000000 vBytes afterwards. And vBytes (or Weight Units) are the unit by which fees are measured.

Also since I haven't seen anyone do this before, let's do the math on transaction sizes under different consensus rules.

Consensus Rule ScenariosConsensus Rule Scenarios

Current Rules: No CISA, 75% witness discount
BIP459: CISA Full-Agg, 75% witness discount
BIP459 + Remove Witness Discount: CISA Full-Agg, No witness discount

Transaction TypesTransaction Types

Simple payment with change (1 input, 2 outputs)
3 UTXO Consolidation (3 inputs, 1 output)
5 UTXO Consolidation (5 inputs, 1 output)
10 UTXO Consolidation (10 inputs, 1 output)
Coinjoin (14 inputs, 18 outputs)
~50 kB JPEG Inscription (1 input with data, 1 dust output)

CalculationCalculation

Assuming the use of Schnorr Signatures.

$w$ is the witness cost factor.

$i$ is the input count.

$o$ is the output count.

TX size without CISA:

f (w, i, o) = 10 + 2 w + i * (41 + 66 w) + o * 43

TX size with CISA Full-Agg (Might be off by a byte or two, depends on how it is ultimatelly implemented):

g (w, i, o) = 10 + 2 w + i * 41 + 66 w + o * 43

Simple payment with change (1 input, 2 outputs)Simple payment with change (1 input, 2 outputs)

Current Rules: $f (0.25, 1, 2) = 154$ vBytes
BIP459: $g (0.25, 1, 2) = 154$ vBytes
BIP459 + Remove Witness Discount: $g (1, 1, 2) = 205$ vBytes

33.12% increase

3 UTXO Consolidation (3 inputs, 1 output)3 UTXO Consolidation (3 inputs, 1 output)

Current Rules: $f (0.25, 3, 1) = 226$ vBytes
BIP459: $g (0.25, 3, 1) = 193$ vBytes
BIP459 + Remove Witness Discount: $g (1, 3, 1) = 244$ vBytes

7.96% increase

5 UTXO Consolidation (5 inputs, 1 output)5 UTXO Consolidation (5 inputs, 1 output)

Current Rules: $f (0.25, 5, 1) = 341$ vBytes
BIP459: $g (0.25, 5, 1) = 275$ vBytes
BIP459 + Remove Witness Discount: $g (1, 5, 1) = 326$ vBytes

4.4% decrease

10 UTXO Consolidation (10 inputs, 1 output)10 UTXO Consolidation (10 inputs, 1 output)

Current Rules: $f (0.25, 10, 1) = 628.5$ vBytes
BIP459: $g (0.25, 10, 1) = 480$ vBytes
BIP459 + Remove Witness Discount: $g (1, 10, 1) = 531$ vBytes

15.51% decrease

Coinjoin (14 inputs, 18 outputs)Coinjoin (14 inputs, 18 outputs)

Current Rules: $f (0.25, 14, 18) = 1589.5$ vBytes
BIP459: $g (0.25, 14, 18) = 1375$ vBytes
BIP459 + Remove Witness Discount: $g (1, 14, 18) = 1426$ vBytes

10.29% decrease

~50 kB JPEG Inscription (1 input with data, 1 dust output)~50 kB JPEG Inscription (1 input with data, 1 dust output)

TX size:

f (w) = 10 + 2 w + 41 + 50000 w + 43

Current Rules: $f (0.25) = 12594.5$ vBytes
Remove Witness Discount: $f (1) = 50096$ vBytes

397.76% increase

Let's put it into a table:

	Current Rules	BIP459 + Remove Witness Discount	Change (%)
Simple payment with change	154 vB	205 vB	+33.12%
3 UTXO Consolidation	226 vB	244 vB	+7.96%
5 UTXO Consolidation	341 vB	326 vB	-4.4%
10 UTXO Consolidation	628.5 vB	531 vB	-15.51%
Coinjoin	1589.5 vB	1426 vB	-10.29%
50 kB JPEG Inscription	12594.5 vB	50096 vB	+397.76%

126 sats \ 0 replies \ @Filiprogrammer 8 Aug

Correction: The change from 12594.5 vB to 50096 vB for the 50 kB JPEG inscription is actually a +297.76% increase.

252 sats \ 1 reply \ @optimism 7 Aug

I don't know. If I will find out a good way in the future, I promise that I will write a BIP, get consensus on the change, all that. Burn out on it if I have to. I just know that I've not seen a proposal yet that hits the tradeoffs at the right spot, so until then, I think we should just practice the philosophy shared in Darth's clip from this morning:

126 sats \ 0 replies \ @DarthCoin 7 Aug

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