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TLDR: The blockchain has the tools to resolve this situation but it would be a huge mess. Longer: The answers there are mostly right. If left to it's own devi

by throwaway2016a 9y ago

TLDR: The blockchain has the tools to resolve this situation but it would be a huge mess. Longer: The answers there are mostly right. If left to it's own devices, the fork will be resolved when the country gains access to the network again. The way it would typically be resolved is that the chain that has done the most work (in a Proof of Work coin) will "win"... in practice this means the one with the longest chain and most transactions. When this happens, the transactions in the blocks that roll back are likely to be added back to the mempool (in memory list of unconfirmed transactions) in which case they will probably still be added to a block. So for most legitimate transactions they might not notice. However, there is a problem here. Adding hundreds of thousands of transactions to the mempool on many coins will cause huge problems. Another problem is if the same output is spent on both forks. Called a double spend. In coins... each transaction has one of more inputs and one or more outputs. Outputs can then be used as inputs to other transactions. Each output can only be used as an input once. If that happens, the transaction that was on the fork that lost will itself be lost since the network will reject it for trying to spend an already spent output. Furthermore, if anyone travels from that country and connects to a network outside of it. They will eventually roll back and join the fork on that side of the partition as that partition will inevitable eventually have more "work done" than the one in the partition they left. Now, if the country never gains internet access again. You effectively have two different coins. But you risk chaos as described above. One possible solution in that scenario is to "hard fork" and have everyone on one side of teh partition install a new blockchain client. Then it's official, they are two separate coins.

raghuvamz 9y ago
Will the miners in both partitions able to mine bitcoins parallely? In that case the average number of blocks mined would take a hit?
- thatcat 9y ago
  You couldn't mine in parallel without installing a miner for each partition.
- throwaway2016a 9y ago
  While technically any transaction made on one partition can be mined into a block in the other partition assuming that the outputs of the previous transaction (inputs to the new transaction) are available in both, in practice it is more likely that transactions from one partition will only end up in that partition and both forks will be very different in terms of which blocks they have. Also, as another reply said, you'd have to have minors connected to both partitions. That is why the fork with the most work wins. Not the fork with the longest chain. Otherwise you could just intentionally partition your machine. Mine a bunch of blocks offline (because difficulty will adjust down as block solve time increases) and then reconnect.
stale2002 9y ago
Here is the thing though It is not just Internet access that the country has to stop. The country has to permanently block off all INFORMATION. This is because if anyone is able to transit the current block chain, in any way, even by smuggling it in through "sneaker net" then that block chain wins. In practice, this means that you will no longer be able to trust 10 minute confirmation times. But, maybe you can trust month long confirmation times instead, as people slowly smuggle in blockchain information.
- KirinDave 9y ago
  This is precisely why infrastructure companies and FIs build dedicated lines. They're much more resilient. Doing so for a network as large as bitcoin could be difficult though.

raghuvamz 9y ago

Will the miners in both partitions able to mine bitcoins parallely? In that case the average number of blocks mined would take a hit?

thatcat 9y ago
You couldn't mine in parallel without installing a miner for each partition.
throwaway2016a 9y ago
While technically any transaction made on one partition can be mined into a block in the other partition assuming that the outputs of the previous transaction (inputs to the new transaction) are available in both, in practice it is more likely that transactions from one partition will only end up in that partition and both forks will be very different in terms of which blocks they have. Also, as another reply said, you'd have to have minors connected to both partitions. That is why the fork with the most work wins. Not the fork with the longest chain. Otherwise you could just intentionally partition your machine. Mine a bunch of blocks offline (because difficulty will adjust down as block solve time increases) and then reconnect.

stale2002 9y ago

Here is the thing though It is not just Internet access that the country has to stop. The country has to permanently block off all INFORMATION. This is because if anyone is able to transit the current block chain, in any way, even by smuggling it in through "sneaker net" then that block chain wins. In practice, this means that you will no longer be able to trust 10 minute confirmation times. But, maybe you can trust month long confirmation times instead, as people slowly smuggle in blockchain information.

KirinDave 9y ago
This is precisely why infrastructure companies and FIs build dedicated lines. They're much more resilient. Doing so for a network as large as bitcoin could be difficult though.