Published on: 2015-08-01T08:43:56+00:00
In an email conversation between Gregory Maxwell and another individual, the possibility of intentionally causing a split in a blockchain was discussed. While intentionally splitting coins between separate forks is possible, there seems to be little incentive to do so since the coins would lose their fungibility and thus be worth less. However, it was noted that new coins and fees would be issued on both chains, which could make it difficult to avoid this fact.Transactions associated with one chain can only exist exclusively on that chain. Someone with single-chain coins can pay small amounts to many users to get their wallets to consume them and make more transactions single chain-only. Migration of miners to the bigger chain was suggested to depend on higher profits due to a higher volume of fees. However, this migration remark was considered oversimplified, as demonstrated by a hypothetical scenario where someone releases software to reassign ownership of a million unmoved coins to themselves at a certain block and then makes transactions to pay high fees. In this case, miners may not immediately move over as they would need to see the new chain gain acceptance through higher trading volume.In a bitcoin-dev email thread, Hector Chu pointed out that there is no connection between transactions and the blocks they appear in. Transactions can be received and accepted in different orders by various nodes. The blockchain resolves potential conflicting transactions by providing a globally agreed total ordering as soon as one of the forks accepts a different transaction in a conflicting set. A split occurs when transactions exist on one chain but cannot exist on the other due to the acceptance of different transactions in a conflicting set. It is possible to intentionally produce such a split to separate the existence of coins onto separate forks, similar to performing a reorg-and-respend attack on a single blockchain.New coins and fees are issued on both chains, becoming spendable after 100 blocks, and any transaction spending them can exist exclusively on one chain. Additionally, any transaction whose casual history extends from the above cases can exist only on one chain. This means that someone with single-chain coins (via a conflict or from coinbase outputs) can pay a small amount to many users to get their wallets to consume them and make more transactions single chain-only.Hector Chu also mentioned that migrating miners to a bigger chain in search of higher profits due to a higher volume of fees is an oversimplification. He provided an example where he could release a version of the software programmed to reassign ownership of a million of the earliest created unmoved coins to him at block 400k and then make a transaction to pay 5 coin/block in fees. In this situation, it may pay more in fees, but whether miners would move to this chain remains uncertain.A forum post highlighted that the discussion surrounding the potential fork of the blockchain due to larger blocks has not addressed what will happen when it occurs. The writer believes that the issue is not as significant as some suggest because transactions on the smaller chain can still appear on the larger chain, and there is nothing tying transactions to the blocks they appear in. However, miners are likely to move to the larger chain to seek higher profits due to increased fees. To prevent this from occurring, changes to the serialized format of transactions on the smaller chain have been suggested so that signatures are no longer valid across chains. Selling off the coins of the losing chain has been proposed, but doing so in the short term is not advisable as these transactions will still appear on the larger chain.
Updated on: 2023-08-01T14:52:32.050512+00:00