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> Bitcoin and other crypto require a well functioning internet infrastructure, otherwise it's just data on a hard-drive. Disconnect a country from the Internet

by nullc 9y ago

> Bitcoin and other crypto require a well functioning internet infrastructure, otherwise it's just data on a hard-drive. Disconnect a country from the Internet (or filter the traffic) and you're forking the chain. Less so than in the past: https://blockstream.com/satellite/menu/ https://blockstream.com/satellite/menu/ > I guess my point is: be careful, this is still very much experimental, don't invest everything you have in them. Well, that much is obvious.

simias 9y ago
Having satellites broadcasting the blockchain is a good step to make the network resilient but it doesn't prevent governments messing with miners. A great disturbance would occur should china decide to unilaterally shutdown the miners on its territory for instance. Furthermore unless I'm missing something these satellites broadcast the blockchain but don't relay new transactions. That means that if I'm stuck in some place without internet access I can use the satellite network to keep my copy of the blockchain up to date but I still can't make new transactions, effectively making it useless. I guess they could expand their services to allow for satellite transaction relay but that sounds very expensive.
- kristineberth 9y ago
  > Disconnect a country from the Internet (or filter the traffic) and you're forking the chain. Is this necessarily true? Forgive my ignorance but if we're talking Bitcoin, wouldn't the rest of the remaining miners around the world be able to account for this? And would the situation be meaningfully different in the country in question were China (or another of similar size/mining power)?
  - simias 9y ago
    I think you're replying to the wrong comment but to try and answer your question if a region is completely isolated from the rest of the bitcoin network one of two things can happen: - If the region doesn't have a significant hash power (the case in most places in the world really) then the block rate will effectively go to zero, meaning that bitcoin will effectively "pause" here and be unusable until fresh blocks can be retrieved from the outside and new transactions broadcasted to the external miners. - If the region has enough hash power to mine new blocks regularly the region will fork its chain. If it has more than 50% of the global hash rate this new chain will be the "real" one and will take over as soon as it's reunited with the rest of the network (invalidating the "outside" blockchain and all its transactions since the fork). If it has less than 50% hashrate then the opposite happens, as soon as the longer outside chain is received it'll invalidate the fork. In both these situations bitcoin is effectively unusable in the minority fork since you know for a fact that the chain will be erased as soon as the network is reunited.
    - kristineberth 9y ago
      Gotcha, thank you for the explanation.
thisisit 9y ago
I read about blockstream some time ago: https://www.coindesk.com/blockstream-using-satellites-beam-bitcoin-earth/ https://www.coindesk.com/blockstream-using-satellites-beam-b... Here Adam Back said: "With a perpetual generator out back with a satellite dish, a Raspberry Pi by the generator, a local wi-fi hot spot, and the necessary software set up, you could be transacting globally with bitcoin." Anyone can explain me why is the need for a local wifi hot spot here? And how much does it normally cost to setup a satellite dish? Not to mention countries do have the ability to jam satellite signals. Here's the first article I find on google search: http://www.spiegel.de/international/world/silencing-unwanted-coverage-iran-jams-satellite-signals-carrying-foreign-media-a-686670.html http://www.spiegel.de/international/world/silencing-unwanted...
- hossbeast 9y ago
  I assume that's just so you can run the wallet on your phone

by nullc 9y ago

simias 9y ago

Having satellites broadcasting the blockchain is a good step to make the network resilient but it doesn't prevent governments messing with miners. A great disturbance would occur should china decide to unilaterally shutdown the miners on its territory for instance. Furthermore unless I'm missing something these satellites broadcast the blockchain but don't relay new transactions. That means that if I'm stuck in some place without internet access I can use the satellite network to keep my copy of the blockchain up to date but I still can't make new transactions, effectively making it useless. I guess they could expand their services to allow for satellite transaction relay but that sounds very expensive.

kristineberth 9y ago
> Disconnect a country from the Internet (or filter the traffic) and you're forking the chain. Is this necessarily true? Forgive my ignorance but if we're talking Bitcoin, wouldn't the rest of the remaining miners around the world be able to account for this? And would the situation be meaningfully different in the country in question were China (or another of similar size/mining power)?
- simias 9y ago
  I think you're replying to the wrong comment but to try and answer your question if a region is completely isolated from the rest of the bitcoin network one of two things can happen: - If the region doesn't have a significant hash power (the case in most places in the world really) then the block rate will effectively go to zero, meaning that bitcoin will effectively "pause" here and be unusable until fresh blocks can be retrieved from the outside and new transactions broadcasted to the external miners. - If the region has enough hash power to mine new blocks regularly the region will fork its chain. If it has more than 50% of the global hash rate this new chain will be the "real" one and will take over as soon as it's reunited with the rest of the network (invalidating the "outside" blockchain and all its transactions since the fork). If it has less than 50% hashrate then the opposite happens, as soon as the longer outside chain is received it'll invalidate the fork. In both these situations bitcoin is effectively unusable in the minority fork since you know for a fact that the chain will be erased as soon as the network is reunited.
  - kristineberth 9y ago
    Gotcha, thank you for the explanation.

thisisit 9y ago

I read about blockstream some time ago: https://www.coindesk.com/blockstream-using-satellites-beam-bitcoin-earth/ https://www.coindesk.com/blockstream-using-satellites-beam-b... Here Adam Back said: "With a perpetual generator out back with a satellite dish, a Raspberry Pi by the generator, a local wi-fi hot spot, and the necessary software set up, you could be transacting globally with bitcoin." Anyone can explain me why is the need for a local wifi hot spot here? And how much does it normally cost to setup a satellite dish? Not to mention countries do have the ability to jam satellite signals. Here's the first article I find on google search: http://www.spiegel.de/international/world/silencing-unwanted-coverage-iran-jams-satellite-signals-carrying-foreign-media-a-686670.html http://www.spiegel.de/international/world/silencing-unwanted...

hossbeast 9y ago
I assume that's just so you can run the wallet on your phone