(The following was a response to a question from Ucy on June 25, 2017, but due to newly available technologies since then this post has been remade and updated a bit).
Re: What if Governments Shutdown the Internet?
June 30, 2017, 07:56:28 AM
from: Ucy on June 25, 2017, 06:45:26 PM
"Pls I need to know something, Is it possible to exchange Bitcoin with other people without being connected to the Internet?
Let say the government bans the Internet and you have your Bitcoin offline(in cold storage right?), can you exchange the Bitcoin to the next person by simply transferring some Bitcoin from cold storage to his/her computer, phone or even data storage devices(like SD Card, USB, Hard drive etc)?"TL;DR: Yes.
See, for example, some discussion of the offline transmission of wood and paper token concept at
https://thecryptosphere.com/2015/05/19/rebuilding-communities-and-identities-with-usb-sticks-and-love-by-anonyodinn/People tend to forget that NFC capacity is built right into bitcoin so that makes it easy to scan and do all sorts of things with, without actually having to have a full "online" system completely operational. There have been whole discussions about transacting without confirmations and consensus (to a certain degree, in other words without a great many people available to do so until a network is developed or recovers) and yes it is possible, I don't want to have this conversation all over again. So I won't even go there. Will not beat a dead horse.
See the total offline setup with minimal hardware requirements (though you'd also need to add some small solar panels and ideally a small battery bank - you can buy all this solar energy stuff you need in REI sporting goods store nowadays - easily and cheaply)
Don't have / don't want / can't get solar energy item / no REI? Fine, just google / duckduckgo / alibaba search the following:
Chinese bicycle powered generator
There's your cheap energy!
And here's how to do bitcoin with no internet. You will be the talk of the town after the energy apocalypse.
https://web.archive.org/web/20170221235057/http://betteroffbitcoin.com/a-protocol-for-offline-bitcoin-over-radio-transactions/Note that you will need to have this set up (with
written instructions about the above on paper) before a major event hits such as a power outage / natural disaster / war problem. But yes. It is absolutely possible and not only that, people are doing it.
Also, it's possible to broadcast bitcoin txs over television (which doesn't require internet and doesn't require MURS radio setup... but if the power goes out regionally so does the TV (in the region of an outage).
See:
https://web.archive.org/web/20160826195212/https://www.cryptocoinsnews.com/kryptoradio-successfully-broadcasts-bitcoin-over-finnish-television-network/It's been done in Finland and I think elsewhere, using DVB-T signal, which covers half the world. By the way, DTMB is used in China, Hong Kong and Macau, so in case you were thinking about it, it's not that far of a leap to figure out a way to transmit bitcoin through tv waves and bypass any current or future Great Firewall controls.
However, I should point out that
it's possible and it's been done to do it via TV, anyway, which doesn't rely upon internet. It's also already been done so it's not just a hypothetical as in "what if we could." Since it has already been done in (a couple) countries, I've suggested (here and also on github in some projects under development) that it also be tried as an anti-censorship mechanism to address problems that users have already experienced transacting with Chinese counterparts.
They will never get rid of their TV, so.... you know, ride the wave.
Finally, this is worth mentioning (although I'm honestly not sure what happens to satellites when there are major systemwide outages - satellites like all things are subject to attack, malfunction, problems etc., but I am no expert on them by any means) -- there is of course the bitcoin satellite project which is intended to reduce the level to which people would need internet for bitcoin to work. So here is the page on that, mentioned here:
https://web.archive.org/web/20170916181834/https://blockstream.com/satellite/from their August 15, 2017 announcement:
"Blockstream Satellite is the world’s first service that broadcasts real-time Bitcoin transactions and blocks from a group of satellites in space. With the service, everyone will have free access to the Bitcoin network, in any corner of the world, including the estimated four billion people not currently connected to the Internet, due to lack of availability or affordability.On launch today, Blockstream Satellite is already available across two thirds of the Earth’s landmass; and will reach global coverage – to everyone on the planet – by end of year. As more people access the Bitcoin blockchain with Blockstream Satellite, we expect to see even more adoption and use cases for Bitcoin as well as a strengthening of the overall robustness of the network."And as a side note, the Bitcoin wiki on Lightning network states in part, regarding "key features," that "payments can be routed across more than one blockchain (including altcoins and sidechains) as long as all the chains support the same hash function to use for the hash lock, as well as the ability the ability to create time locks." This is doable now that Segwit is done. Such features will not emerge immediately, but will occur in the future (1-2 years time down the road). This will actually generate further resistance to censorship.
