What are the side effects of 15% of "extra" empty blocks?
1) The difficulty increases. This is good for the network, but bad for miners
2) It takes longer for transactions to make it into blocks.
Am I missing something? Neither one seems like THAT big of a deal.
Topic: Miners that refuse to include transactions are becoming a problem - page 13. (Read 16972 times)
March 19, 2012, 01:22:35 PM
March 19, 2012, 12:43:46 PM
Not relaying "smelly" blocks is a very interesting idea.
It doesn't have to be a binary relay/don't relay... you could immediately relay good blocks but wait a while before relaying bad blocks, and make the length of time you wait to relay based on how bad you think they are (maximum of maybe 10 minutes before you relay).
But... not relaying new blocks immediately might just encourage the bad guys to try to connect directly to as many nodes as possible, and that could be bad for network health.
It doesn't have to be a binary relay/don't relay... you could immediately relay good blocks but wait a while before relaying bad blocks, and make the length of time you wait to relay based on how bad you think they are (maximum of maybe 10 minutes before you relay).
But... not relaying new blocks immediately might just encourage the bad guys to try to connect directly to as many nodes as possible, and that could be bad for network health.
March 19, 2012, 11:00:13 AM
I hadn't realized this problem had gotten so bad so quickly. Clearly including transactions for fees isn't a great enough incentive. I agree it should be addressed.
I've always thought relay nodes should take a greater role in security. If they refuse to relay blocks that don't include at least 80% (measured by fees to prevent cheap transaction spam) of transactions they've seen since the last block it might solve it - no-transaction blocks would have very poor propagation and therefore would be highly-orphaned, giving a big economic incentive for them to play nice.
On the other hand I'm not sure how well this would behave in circumstances where there is a major network split with only a few nodes holding it together. If the two halves of the net aren't seeing most of the other side's transactions and the couple relay nodes between are dropping both side's blocks (due to failures to include), could that worsen the problem? The couple bridge-nodes would of course be relaying transactions across to both sides, but I'm concerned if it was compounded by other problems causing poor propagation.
I've always thought relay nodes should take a greater role in security. If they refuse to relay blocks that don't include at least 80% (measured by fees to prevent cheap transaction spam) of transactions they've seen since the last block it might solve it - no-transaction blocks would have very poor propagation and therefore would be highly-orphaned, giving a big economic incentive for them to play nice.
On the other hand I'm not sure how well this would behave in circumstances where there is a major network split with only a few nodes holding it together. If the two halves of the net aren't seeing most of the other side's transactions and the couple relay nodes between are dropping both side's blocks (due to failures to include), could that worsen the problem? The couple bridge-nodes would of course be relaying transactions across to both sides, but I'm concerned if it was compounded by other problems causing poor propagation.
March 19, 2012, 10:20:44 AM
At first I was thinking we could treat empty blocks as invalid, but the attacker might just add a few pre-made offline transactions to his botnet code and still keep it more secretive than a full bitcoind.
The best solution I can think of is to slowly lower the subsidy over many years, while developing specialized hardware to outperform botnets.
I remember hearing somewhere that Satoshi wanted to upgrade the transaction fee system before he left, does anyone have any further reading?
The best solution I can think of is to slowly lower the subsidy over many years, while developing specialized hardware to outperform botnets.
I remember hearing somewhere that Satoshi wanted to upgrade the transaction fee system before he left, does anyone have any further reading? 
March 19, 2012, 08:16:18 AM
Currently we have a situation where a major solo miner, most likely a botnet, is mining Bitcoin blocks without adding any transactions to them. Approximately 15% of the network hashing power is currently creating blocks that do not have any transactions in them. There is a large thread about this in the mining forum: https://bitcointalksearch.org/topic/wonder-who-this-solominer-is-8862169-67634
So far it seems to be unclear why this is done, with most setups it shouldn't matter from a bandwidth/cpu point of view if he adds transactions or not. Clearly he has a reason for this and it could be either that he has found a way to mine less noticeable with infected PC's by not adding transactions to blocks OR he is doing this with malicious intent, perhaps trying to hurt Bitcoin. That could prove profitable to him if he short sells BTC at the same time, especially if he is planning to add more hashing power.
At the moment he has only 15% which is not a real threat to the network but what if it rises to 30%? Then one third of all blocks refuse to include transactions. Developers should take this seriously, it's in my opinion a high priority. We should start solving this before it becomes a bigger problem, and it definitely could become a major issue.
I'm not interested in speculation of why he is doing this. All of the possibilities are bad, some are just less bad than others. I'm interested in finding a solution, some way that we can fight this. Perhaps by making it less profitable to just mine blocks without adding transactions.
So far it seems to be unclear why this is done, with most setups it shouldn't matter from a bandwidth/cpu point of view if he adds transactions or not. Clearly he has a reason for this and it could be either that he has found a way to mine less noticeable with infected PC's by not adding transactions to blocks OR he is doing this with malicious intent, perhaps trying to hurt Bitcoin. That could prove profitable to him if he short sells BTC at the same time, especially if he is planning to add more hashing power.
At the moment he has only 15% which is not a real threat to the network but what if it rises to 30%? Then one third of all blocks refuse to include transactions. Developers should take this seriously, it's in my opinion a high priority. We should start solving this before it becomes a bigger problem, and it definitely could become a major issue.
I'm not interested in speculation of why he is doing this. All of the possibilities are bad, some are just less bad than others. I'm interested in finding a solution, some way that we can fight this. Perhaps by making it less profitable to just mine blocks without adding transactions.
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