Bitcoin Forum

Since February 2023 mempool almost not empty and i thought that 2-3 biggest pool can spam mempool with low-fee transactions just to get more fee.
Just check out this block: https://mempool.space/block/0000000000000000000421dea73b197dec0c1c57a4620c274b7b048c1786c35b
all block is full of $0.08 cent transactions with $0.24 cents fee.
Probably we need additional compression for transactions like this because that all have same amount, fee and OUTPUT address, or some other solution.
I heard that Stratum V2 firmware can potentialy solve some problems by giving more freedom to individual miner, which can avoid this transactions.
What are you thinking about it ?

Such transactions are spamming the network and have caused transaction fees to be higher, but it's not true that they are created by miners.
There are many other transactions similar to those you are talking about in other blocks and in the mempool and they are all related to ordinal scams.

I think this is somewhat similar with dust attack tho I just know it today, But if this spamming Bitcoin work we should see the spike in Bitcoin fee in the next block but after watching your Block transaction the next block and other blocks are still at the 6 sat/vb.

Maybe your theory is correct, just like how Antivirus companies spread virus over Internet, miners (not all of them) might be adding these transactions to the the network just to get more fee.
It's a possibility to be very honest. How about you do some research and try to gather intel if these are actually miners who are doing it or it's due to the BTC Ordinal stuff? That's what I guess it is.

So are all other blocks at that time, what's so special about it?
Besides, it's not full of 8 cents fees, it also has stuff like this in it:
https://mempool.space/tx/34c4240978cc8497a82f3770e6e68ba43cd1e040b1135be91caf4cd3971665e5
Fee   3,832,070 sat $1,107


What is wrong with those transactions?
They are valid transactions, getting accepted by nodes, and they pay the fee just like others, who are you or anyone else to decide what should be allowed and what not? Besides, the individual miner, unless he somehow manages to get 2-3 Exahash of hashing power so, about 10-20 thousand miners at least can't and won't be able to do a thing.

Yeah, let's start censoring stuff we don't like because obviously, that's what Bitcoin was designed for!
Next will be thumblers and mixers because they make hundreds of tx, then there will be consolidations cause they also take too much space, then transactions under 10$ cause they present no interest then banning transactions between same wallets as they also clog the mempool, then miners won't accept transactions unless the owner of the originating address hasn't already submitted a sperm sample along his KYC data.

Guys, we must stop our mempool from being spammed.

There is a problem with the transactions spam attack, and the problem is that you have to pay for each transaction. So, for an attack like this you need to spend a big amount.

Is the same as a business paying for marketing campaigns to get more sales, miners pay fees to increase the fees by priority. But is not the best strategy because your competitors (the other miners) get the same high fees benefit on each mined block when the mempool is full.

Stratum V2 will make people who don't have a lot money can't start to mine, so we can expect Bitcoin miners are probably like top 5-10 big companies. It will make them easier to reject some transactions since there are only few miners.

But I doubt it because miners are profit oriented, so they high likely will accept any transactions regardless it's Bitcoin or shitcoins that run in Bitcoin network.

How? however currently the mempool is already normal.

Miners are not the only ones benefiting from higher transaction fees but some altcoins and exchanges, in 2017 there was a high volume of hashtags to support the BCH hypothesis and prove that Bitcoin is not suitable for everyday transactions.
Miners are the weaker party in the spam attack, as they do not make a profit from it, but on the contrary, the spam transactions that they make make the block full, while it could have been to include more transactions in that block and earn more fees.

If you think the fees are high, stop sending transactions.

The opportunity cost of including these transactions would be those that could have been included to give the miners a higher profit. That would make sense if there is a collusion among the miners to artificially inflate the fees but generally game theory negates all of these collusion and would result in a far lower profit than expected.

Besides, the fact that most wallets are biased towards mempool size rather than historical block data as a fee estimation makes this less likely to influence the fees to a large extent.

The problem started since the inception of the scam Bitcoin ordinals, and everyone who loves Bitcoin hates them. Very many times the discussion to block such a thing has gone up to the level of Bitcoin developers, but they just decided to let it be.
Obviously we know the ordinals hype will fade up with time but until then we just have to hang in there

That doesn't make sense because the miner would be paying the fees that they earn. Why would a miner to fill a block with their own transactions that effectively earn them nothing when they can include transactions that earn something?

If a miner doesn't want to include transactions with low fees, then they just don't include them. Its not clear why a miner would do that because the miner would be giving up money for no benefit.

Exactly. As I said in the first reply, those transactions are related to ordinal scams and are not made by miners.
If such transactions are made by miners, not only they don't earn any money from them, but they also waste some money. All those transactions are creating dusts and it would be very expensive to spend them.

Although the possibility of mining pools spamming the network is not zero but it is not that common because the mining pool doesn't receive the fees even if they don't let the rest of the network see the spam transactions and mine them all themselves. The fee is paid to the miners based on their share of the hashrate. In other words this is a very costly attack for the pool.

BTW you can't just find spam by looking at the raw fee in dollar paid by transactions. Actual blockchain analysis is needed.

I've had began a similar thread a little while ago, check it out: What happens if pools try to maximize fees by congesting the network? (https://bitcointalk.org/index.php?topic=5455793.msg62377070#msg62377070). My conclusion is that it requires coordination between miners, which can go against game theory.

It'd be the same as mining an empty block, with the exception that if another miner mined that block, they'd take those miners' transaction fees.

To trick those others into paying more with replace-by-fee, to get better priority.

That's worse than mining an empty block.
The transactions OP is referring to have created outputs worth 294 satoshi which is equal to the dust limit. Assuming those transactions have been made by a mining pool, the mining pool have lost money even if the transactions have been mined by themselves and we neglect the computing expenses.

Sure, these particular transactions they describe make the entire process more expensive, because when the time comes they spend these, they'll have large sized transactions. But, the same attack can be executed without adding anything to the UTXO set, say sending 0 sat to OP_RETURN.

block has over 5k tx
imagining it made 5000 tx of 294sat is less than $400
block reward of 6.25= $163,000
seems the pool still made money

As I pointed out above the pool doesn't receive the block reward+fee, the miners do. The pool itself only take a percentage for the service they provide. That means if the pool had indeed paid $400 in spam fees, they have indeed lost money.

These redundant low-fee transactions clogging the mempool, though? It's an attack on decentralization itself

This block shows what humans will do when they can utilize an opportunity. None of this surprises me. Greed is human nature. Large pools spamming the mempool is a nasty act of centralized authority gaining control.

V2 stratum? While it promises to allow miners to level the scales, no single solution is a panacea. Strategies to exploit systems will always exist. A cat-and-mouse game.

We need a community-wide ideological transformation, not just another answer. Time for communal self-reflection and action. It's not what I think, but how ready are you to fight these exploitative strategies?

This is correct, and something I hadn't thought of. In order for the attack to pass, the miners have to agree that they will not be paid for every transaction in the candidate block. This is quite of a big disincentive already. Miners must share the fees equally to the work they've provided, otherwise the pool has no incentive to not arbitrarily lie about some, and take their income without explanation.

Even if what you are saying is true still it is not harming the Bitcoin users, the fee required to make your transaction is 7sat/vbyte which is considerably low. If they really want to push the network to increase the TX fees then they need to fill the blocks with high TX fees transaction which will obviously going to be a loss for them so they can continue to spam the network with low fee TX and make less profit than they used to be or just do nothing at all to make more profits.

I think best what we can do is propagate to avoid big pull, because this attack has to be created from 2-3 biggest pool and that attack with fee which a bit lower than average.
Hopefully, lightning network and liquid network will reduce payload of mempool with enough power to prevent such attack on feature.
Big disadvantages for miners which i see with attack like this that hashrete still grove up what means that miners grove up potential concurrent for themselves.
If this problem will rise for next 5 years (till 2028) we will need new discussion and probably new spam detection software which should filter same amount with same fee transaction and some bitcoins freeze if that transferred in last 2 days.

This block is a good example of this type https://mempool.space/block/0000000000000000000173b690c0f0cdef738eebaaafea82b75c95f253a56f2f

Not really. That is the monetary cost, but in economics then we would consider the opportunity cost. Hence, if there is another 5k transactions that has a tx fee of 1sat more, then you would have lost 5k sat by not including those transactions.

Fortunately, same as the prisoner dilemma problem, the collusion is harder to pull on with this much money and unpredictability involved.

weird.. your worrying over a 1sat increase of 5000tx = $1.31 total
and worried about 5000tx of 294sat =$400 but still ignoring the $160,000 income

the concern over $401.31 vs $400 is not something pools think about much because the $160,000 is still more important

we are still in the era of block reward=income, fee= bonus.. we have yet to reach a threshold where the mindset flips to
fee=massive commissions where the reward is the negligable unimportant income

do you know that most pool manager economics thoughts are that if they can create their own set of TX they own. they do not need to worry about including other peoples tx. and thus by not having the worry of accidentality pre-collating transactions that may end up in someone else block(thus having to stop and re-collate a new set of tx). means they can shave a few seconds on their own block attempts and thus have a greater chance of winning the latest fastest block. thus winning the $160k with greater chance
yep some pools sacrifice the small fee income to get better luck solving more blocks faster to get the larger main reward

That is not how economics work. Well, it would be logical if you're talking about some ulterior motives that compels miners to only have transactions which has low fees. In a game theory approach, if you have agents that wants to maximize their profits, then they must include transactions with fees. The extent of which should be as much as possible, because people would hop to another pool if they don't.

The block reward isn't negligible income and it is definitely included in the PnL calculations before we invest (ie. we estimate how much of our profits could come from fees). There's a pretty big difference between making money, which is in your case making $160,000 but not making $160,001 when there is little to no cost.

That's not true at all. If a miner were to only include their transactions, they stand to not benefit at all because they are paying their own fees. I think you're talking about empty blocks: Faster propagation, no risk of invalid blocks without validation.

Block validation is in the range of a few milliseconds. Sure, you can send an empty block template but you would never send a block template that has tons of tiny transactions. That only slows down your propagation while receiving virtually no benefits.

firstly MINERS are just ASIC's they just hash
they have no control of the transaction selection... dont confuse miners with pools

secondly there are pools that offer miner reimbursements as 0 fee but 100% reward. or X% fee 9X% reward whereby fee's are still negligible to miners because the cut the pool takes would offset any gains from fees so many miners dont pool hop depending on if a pool does or does not include transactions. most miners stick to a pool that has best luck of block solving no matter how many tx's are included, no matter if its high or low fee tx included.

you will surprise yourself when you see that there is a lack of pool hopping happening when a pool collates low fee's or does empty blocks. because most miners are not watching block explorers to check how many transactions are in a block. they just count block solves/wins and how many shares of that block reward they get

they care more about how many shares of a reward they get in regards to how many other asics are on the same pool and how many block solves are done by pool per hour.. they dont transaction fee count

It's ironic, and laughable, that those who support the "BCash hypothesis" is making an example of something that gives a stronger debate to regulate the size of the blocks. 8)

Eh, that is a new learning for me from the community. I never thought there would be way out to spam the pool by doing multiple transactions with lower fees. However, I do not understand the ideology behind this? What is the benefit to whoever this person or entity is and doing such random transactions with penny transfers? What is in it for them.

As I read there is one answer only miners can benefit from this because they will have increased transactions and also they will be able to raise the fee structure if pool gets congested. I am not sure how true that could be but it seems that they are making full use of this loop hole. Is it a loop hole and we can't really do anything about this?


From this post it does seem like miners benefit more than the pool from this strategy.

Anyways, what about the users, aren't they getting looted in the war of pool and miners?  ::)

What feeds the miner? There is something that has to build the merkle root and the block headers. Whoever runs the ASIC has to make deliberate decisions to include or exclude transactions.
Exactly. Miners hop to pools that provides the most profits. Pools are not charity, they do not give out money for free and there is always a catch if they are seemingly running it for free. That is also the naive approach, for which no one actually adopts. Luck does matter and miners can pool hop. The profitability is still attributed to the fees being paid out from the blocks, and there is no denying that. If they don't, please point out a pool that doesn't include the highest fees.
They don't but the observation of a lower potential profit is far more obvious in the long run. It doesn't matter what an individual miner perceives. A rational miner always maximizes profit, and empty blocks or intentionally including lower fees isn't one of them. If that is, then pools would be actively doing it.

Concluding note: No free lunch in the world and each miner is paying for their services to provide them in the form of a mining pool. If you collect less fees, then you are receiving less profit, because your fees are pegged in the miner's revenue. Additionally, including low fee transactions or not including transactions doesn't affect stale rate to any noticeable extent.