Bitcoin Forum

i saw a few of these scroll by on blockexplorer.com in the past few days: blocks with zero tx besides the BTC 25 award to the miner. have also seen some with just a few tx in them.

recent examples are 234221 and 234217.

am i missing something here or is someone mining empty blocks? seems like a rude thing to do. i am guessing there is some edge to mining empty blocks.

I have seen some speculate that mining empty blocks could be some kind of attack vector. I don't really understand it well enough to explain, but creating a fork of empty blocks is easier that full blocks.

the immediate consequence i see is that tx during that time period must wait to be included in the next block, which is more irritating than anything else.

i'm sure i could figure it out if i dig, but maybe someone here knows who is doing this. not unreasonable to single these people out because they are kinda fucking up the infrastructure.

The protocol supports mining blocks that have only a coinbase transaction.  There is no technical obligation that miners include additional transactions in their blocks.  Of course failing to include additional transactions means that you miss out on all the transaction fees from those transactions, so it generally hurts the miner more than the rest of the network.  The one reason I've heard that a miner might choose to not include transactions in the blocks was in the case of a trojan mining bot.  The distributor of the trojan would want to minimize the amount of information that the bot needed access to, and could reduce this to simply the hash of the previous block if they didn't include any transactions.

Unless they control a significant percentage of the mining power, how can they fuck up the infrastructure? They waste their resource in exchange for just a small delay in the processing of transactions.

If that is the case, hypothetically taking the blocks as attacks, it could cause one or two people to complain about delays and generally cause a bitcoin price fluctuation that allows the attacker to aggressively enter the market beyond just mining blanks.

"empty" blocks (like all other blocks) don't delay non-empty blocks from being solved

to be precise, after the difficulty readjusts, they would delay waiting for a non-empty block by

(10 min) * (their share of the network hashrate during the previous 2016 blocks)

which is negligible

There was talk in the p2pool thread of someone modifying p2pool not to include transactions to gain less rejects as it reduces lag.