83
84

Miners self-stuffing transactions to drive up txn price? (self.Bitcoin)

jlcooke が 投稿

AntPool's recently mined transaction: 0000000000000000009be466106d868431a2d1aa946f529523048ee27f2deeaf sends 12.5btc + txnfees to 1L75eRMgeCwAxEjD1oWXjLgud9jxwxm34u

Here's where it gets interesting:

txn ecdb84be09bc9356cc0cff7aef3a93404fa13686d27d67feacf62740388720d1 value 400BTC has 8 inputs from 1L75eRMgeCwAxEjD1oWXjLgud9jxwxm34u into 2 addresses (Size: 4212 bytes @ 42sat/B). Weird to send yourself multiple amounts in the same transaction - but not a big deal, I guess.

One of these addresses 1F4JZYZr4rQhFeJ9P4N9ZL2cHe5cPsbnxw sent a 400BTC (3565 bytes @ 316 sat/B) transaction to about 100 tiny destinations (less than 0.01btc). But one stands out - 399btc 16jY8U2PodHZ79jKkSvjzVYoAjVQTpu6Q8 - it outputs to another 100 tiny transactions.

Repeating this search backwards in time we see this pattern repeating almost every block reward for AntPool / Bitmain.

The connections:

  • Antpool expects to get 40% of its transaction fees back via block reward
  • Antpool creates quite a few small dust transactions
  • Antpool pays premium fee rates

The questions:

  • Is Antpool (and other miners) gaming the fixed-size transaction fee market? Do we even care?
  • Is Antpool (and other miners) holding their BTC until after a potential hard-fork this driving up BTC prices before they open the flood gates and sell? Do we even care?

The "do we even care" part is not facetious. Maybe we really don't.

[edit: formatting]

全 35 件のコメント
並べ替え:
ベスト
トップ新着論争中古い順Q&A

[–]etmetm [スコア非表示]  (1子コメント)

There was some talk a while back that some entities are sending tx (with unconfirmed parents) round and round with highish fees to possibly influence fee estimation upwards.

Can't find the reference but possibly what you're seeing. Fee estimation needs to get even smarter to avoid being fooled this way, and chances are this is being worked on already

[–]crawlingfasta [スコア非表示]  (0子コメント)

That's clever (in a borderline evil, monopolistic and short-sighted way.) Solving the fee estimation problem seems pretty important in the short term.

I had trouble finding the discussion (because reddit's search feature sucks) but if anybody has the link, please post it.

[–]Cryptolution [スコア非表示]  (1子コメント)

Do we even care?

Hell fucking yes we care. Do you see the madness we have had to put up with for the last year over fee rates?

So lets get this straight -

  • Miners artificially increase fee rate while blocking upgrade that would reduce fee rate

  • Miners use politics and claim open source developers that released solution are evil and bad actors and instead encourage horrible can-kicked-down-the-road "solution" that preserves their asicboost instead.

  • Miners use stall and divide tactics to rile up the social bees nest and create toxic and hostile environments in the ecosystem.

  • Then miners agree to run a proposal that gets their supposed "solution" even though by the time its activated it wont even be necessary and puts the ecosystem at risk for no apparent reason. All because a "opt in" upgrade that would have allowed the system to have lower fees and smarter scaling was blocked by them.

Did I miss anything?

[–]evilgrinz [スコア非表示]  (0子コメント)

Look at the other thread about low mempool, there are alot of bizarre posts in it. I think this is definately in play.

[–]CaptainOuzo [スコア非表示]  (0子コメント)

has 8 inputs from 1L75eRMgeCwAxEjD1oWXjLgud9jxwxm34u into 2 addresses

What's weird about that? 1 address is the destination, 1 is the change address.

about 100 tiny destinations

Mining pools pay numerous separate miners. That's the whole point of them.

I think Bitmain is a major centralization risk, but the transactions you linked to are what I'd expect for a mining pool. Nothing stands out as being odd. If anything it's evidence that Bitmain is getting a considerable amount of third party hash power pointing at them. That makes me wonder why people don't point elsewhere. I've heard that Bitmain basically bribes people (via hardware discounts) to point their miners at Antpool.

According to this source Antpool's minimum payout is 0.001 BTC. All of the hundreds of transactions you point out are above this value, so they are consistent with paying miners their daily earnings.

[–]Thisisgentlementtt [スコア非表示]  (12子コメント)

I have played around with this idea quite a lot and ran a few test scenarios. My conclusion was that this indeed is possible and also profitable for a large enough miner. I also wrote a longish post on the subject but after pondering on it for quite some time decided not to publish it.

Why not publish it? Firstly because I try not to participate in the blocksize debate (in my opinion, this "profitable spamming" is made possible because the blocks are full/almost full) and secondly I actually came to the conclusion that "It does not matter." For short term this is bad of course, but in the long term if Bitcoin is as antifragile as is believed, it will self correct somehow.

[–]arcrad [スコア非表示]  (7子コメント)

How do bigger blocks solve the profitable spamming policy? Why can miners not just fill up more of the bigger blocks and achieve the same inflated fees?

[–]wachtwoord33 [スコア非表示]  (0子コメント)

Indeed.

[–]dontthrowbtc [スコア非表示]  (2子コメント)

Dont the cost go up the bigger the blocks are? Or does the potential profit also go up?

[–]s0cket [スコア非表示]  (0子コメント)

Just the cost really. You can't artificially manufacture legitimate use of Bitcoin. There is only finite pool of transactions to draw inflated fees to profit from.

[–]mmortal03 [スコア非表示]  (0子コメント)

Not if they also find a way to offload the externality cost of bigger blocks on to others who aren't being compensated for serving up the bigger blockchain to the network. I mean, miners don't need to run full nodes if someone else is doing it for them, right?

[–]s0cket [スコア非表示]  (0子コメント)

It wouldn't solve it. But, it would make it harder for it to be profitable. The next step is to build blockchain analytics to develop a index to track this kind of behavior. Then wallets can use the index to help decide a proper fee.

[–]jaumenuez [スコア非表示]  (0子コメント)

How do bigger blocks solve the profitable spamming policy?

They don't, that means bigger blocks solve nothing. Anyway miners are not after their own fees, they want to open a gate to their own transactions with lower fees. Businesses associated with a mining pool will get free entry in their blocks. The rest of us will have to pay. LN opens the gates to many other players.

[–]Middle0fNowhere [スコア非表示]  (0子コメント)

The more the blocks are "naturally" full, the less monetary risk has the "spamming" for spammer.

[–]jaydoors [スコア非表示]  (0子コメント)

It really matters if it's true. You have the network costs and bloat of full-size blocks, for the transaction throughput of much smaller blocks. And as long as miners can choose transactions, it's hard to see how this would stop. An over-bloated blockchain is not something you can "correct".

Thing is, you wouldn't expect it to be possible without collusion - an individual miner would be irrational to stuff a block with their own transactions and forego real ones with fees. So if it's happening it's quite worrying as it probably means a substantial majority of hashpower is being controlled by a single entity.

Also it is an extremely strong argument against big blocks - as it implies that, whatever size permitted, they will be stuffed by miners until the same number of real transactions are included as we have now.

[–]ziggamon [スコア非表示]  (2子コメント)

I agree with "it does not matter", but for the sake of science it'd be great if you published it, I know I'd be interested in reading it.

[–]jaydoors [スコア非表示]  (1子コメント)

I think it matters a lot.

(from another post I made in this thread)

It really matters if it's true. You have the network costs and bloat of full-size blocks, for the transaction throughput of much smaller blocks. And as long as miners can choose transactions, it's hard to see how this would stop. An over-bloated blockchain is not something you can "correct".

Thing is, you wouldn't expect it to be possible without collusion - an individual miner would be irrational to stuff a block with their own transactions and forego real ones with fees. So if it's happening it's quite worrying as it probably means a substantial majority of hashpower is being controlled by a single entity.

Also it is an extremely strong argument against big blocks - as it implies that, whatever size permitted, they will be stuffed by miners until the same number of real transactions are included as we have now.

[–]GratefulTony [スコア非表示]  (0子コメント)

a substantial majority of hashpower is being controlled by a single entity.

http://i.imgur.com/cRaR2VI.gif

[–]pearlnecklaceringredditor for 0 days [スコア非表示]  (0子コメント)

it is all becoming more artificial than just being virtual

[–]rivierafrank [スコア非表示]  (2子コメント)

Yes they are driving fees up, its simple math. How much it costs in fees to drive up price vs how much they get in fees from blocks. edit: but not necessarily from these transactions which could just be payments

[–]kattbilder [スコア非表示]  (1子コメント)

I doubt it, as you also were hinting at, although it is a significant (theoretical) risk as a result of miner centralization.

Yeah probably it is real usage, but sure, miners have every incentive to increase the amount of bitcoin per block, in whatever way. Their macro-incentives relies on the success on bitcoin, but that's not really how we do game theory.

To elaborate, in order to fill blocks with crap transactions, it costs a certain amount. The colluding miners would have to trust each other well enough, because it would either be detectable by blockchain analysis and verifiable by the cartel. Or in the case of a gentlemens agreement without traceable stake, be vulnerable to cheating among colluding parts.

Feel free to point out flaws in my reasoning.

[–]rivierafrank [スコア非表示]  (0子コメント)

i dont see any flaws. its possible the reward of spam transactions is so high that they are all aligned on the same objective by default, or even that cooperation of others is not considered.

[–]Follow_cLear [スコア非表示]  (0子コメント)

why does this thread has only 20 upvotes wtf

[–]RufusYoakum [スコア非表示]  (1子コメント)

As a miner you can

1 - Fill the block with your own transactions paying yourself with your own bitcoin

2 - Fill the block with other peoples transactions paying yourself with other peoples bitcoin

3 - Produce empty blocks

Seems like #2 has better incentives.

[–]jlcooke[S] [スコア非表示]  (0子コメント)

Agreed. But you can also increase revenue from other people's transaction fees by artificially congesting the transaction pool.

Some live txn fee stats: http://bitcoinfees.21.co/

[–]berepere [スコア非表示]  (0子コメント)

Is Antpool (and other miners) gaming the fixed-size transaction fee market?

I wrote this post a while back explaining why this is easy, cheap and profitable even for a small miner - doesn't have to be anything as big as Antpool.

[–]RoofAffair [スコア非表示]  (0子コメント)

Another question that should be asked; how many of the transactions within any given block had been previously seen in mempools?

It's possible to make these transactions and never broadcast them. Effectively allowing the pool to guarantee they mine back those transaction fees as it wouldn't have been seen on the network by other miners. Doing so could mess with fee estimates that look at the previous blocks average fees.

This may also help with ASICBOOST as well. Using self created transactions you can maintain the appearance of a full block, while including a majority of transactions you created before hand.

[–]no_face [スコア非表示]  (0子コメント)

One option is to have a fixed fee rate for any utxo over say 24 hours old.

[–]Ignatius_G_Reilly [スコア非表示]  (4子コメント)

Bitcoin proof of stake when?

Edit: downvoted by jihanis

[–]kattbilder [スコア非表示]  (2子コメント)

Proof of Stake requires subjectivity in what to trust, I fail to see how it cannot be gamed (requiring a hardfork like eth/etc).

I think this is the general consensus among Bitcoin users and developers.

[–]Ignatius_G_Reilly [スコア非表示]  (1子コメント)

I have read a lot of arguments for and against PoS and based on prior examples (NXT, peercoin, BTS etc...) and the exciting research (Casper) going on at the moment I can not seriously believe Proof of Stake is a proven impossibility. There are many different implementations and methods to realise this vision. PoW also requires some level of subjectivity (UASF)

[–]kattbilder [スコア非表示]  (0子コメント)

I sure hope it can work.

Yes it is somewhat philosophically similar!

[–]thieflar [スコア非表示]  (0子コメント)

Downvoted by people who understand Bitcoin.

[–]phatsphere [スコア非表示]  (0子コメント)

for me this isn't surprising. it's also no surprise to me that segwit is considered unfair because it penalizes transactions with a large number of outputs.