You need an input that is invalid on one of the chains in order to safely spend on the other chain.
This could be a coin base mining reward specific to a chain (or children of it).
Also, you might manage to get a transaction to verify in one chain, then "double spend" (not really since its a different chain) those same coins to a different address on the other chain. Once they are confirmed to different addresses in each chain, they would be separate. This method is more complicated, but may be made easier due to different block sizes (get a low priority transaction confirmed in a large block size chain, then rebroadcast it with a high fee to a miner on a small block size chain). You could keep trying (sending coins to yourself so there is no risk) until you finally manage to get them separated.
I don't know of any other methods.
This could be a coin base mining reward specific to a chain (or children of it).
Also, you might manage to get a transaction to verify in one chain, then "double spend" (not really since its a different chain) those same coins to a different address on the other chain. Once they are confirmed to different addresses in each chain, they would be separate. This method is more complicated, but may be made easier due to different block sizes (get a low priority transaction confirmed in a large block size chain, then rebroadcast it with a high fee to a miner on a small block size chain). You could keep trying (sending coins to yourself so there is no risk) until you finally manage to get them separated.
I don't know of any other methods.
Hmm, thats because transactions or inputs/outputs don't reference a block hash, right?
If they somehow referenced a block a node could validate that the block exists on the chain it sees.
Would that be possible as a change? It would require a softfork I think.
Moving coins from one address to another, for each block, hoping to separate them could be a very long process. Especially since for a few weeks after the fork the block-size of XT is likely to still be mostly below 1 mb.
There is no way to craft a transaction to get it accepted on one chain but not the other?
It seems separating the coins is actually very difficult to accomplish. Can anybody think of some other mothod?
