You can create and sign a transaction while the Internet is off (with your wallet software).

You can transmit that signed transaction however you like (over radio, carrier pigeon, etc.) but you can't have that transaction "confirmed" and added to the blockchain until you submit it to the Bitcoin network.

Be careful with these "offline" payments, because nothing prevents someone from "spending" their funds more than once, and only one of the transactions will be able to be confirmed by the network.

There was a radio station from Brazil if I remember correctly that was aiming to do exactly that.  Send Bitcoin through radio.  How easy or accessible that is to do however and under which circumstances, I do not know.  Nor can I find the link anywhere on the Internet, maybe someone else could give it a better search.

Larger issues arrive when you are doing short distance transactions though.  If the Internet is offline, I think it becomes extremely easy to create illegitimate Bitcoins and scam others into believing they are real.  That is because there are no more peers, there is no more network.  Therefore, how do you broadcast and how do you receive the confirmations?

If there is no way you can broadcast transactions and receive confirmations, it is easy to scam.  I could have 3 laptops on me.  All disconnected from the Internet and having the same Bitcoin wallet on them.  I could meet up with 3 different people and 'send' them 1 Bitcoin each.  Although I actually own just 1 Bitcoin, I just multiplied it by 3 because my wallets are not connected to any network to verify double spending and the transactions are not being broadcasted anywhere.

Similarly, a local mesh network could be malicious by running a Bitcoin chain that is mining blocks different from, say, the one running at the time under a local mesh network in Germany.  Because our local mesh network has no connection to the local mesh network from Germany, at the time the two connect, as far as I understand the longer chain becomes invalid.  And that would create a TON of problems.

By having the Internet shutting down, I think Bitcoin is doomed really until the network is back up.  But on the other hand.  If the Internet shut off for even a day, would the entire world not turn into a chaos of such a large scale it would be so much more important to prioritize food and survival over anything else, including cash and Bitcoin?

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Regards,
PrivacyG

To put it simply, yes you can. A Bitcoin transaction is nothing more than a piece of digital information like any other. If you can send and receive information via HAM radio from/to the Internet, then you can do the same with Bitcoin transactions. However, whenever you transmit information about a signed Bitcoin transaction, someone on the receiving end must have a HAM radio connected to the Internet to be able to broadcast your transaction to the Bitcoin network.

Um, in what sort of reality does one live to think that the US or any modernized country would ever 'shut off the internet'? For virtually all countries these days ALL communications be it telephone, data exchange, video, etc. sooner or later runs through the internet so any country deciding to block the networks in said country is simply NOT EVER going to happen unless they want to commit economic suicide. As for any country being able to globally kill the internet, again that is simply NOT possible because by-design the networks WILL find other routes to re-establish the links needed to find each other.

I agree it’s highly improbable. However, it’s the #1 criticism I hear, and it’s not impossible. The United States has an internet kill-switch, and it can be pulled by any president. Russia has temporarily shut off their internet to the rest of the world, and China is making it increasingly harder to use VPNs and Bitcoin. I don’t see this happening anytime soon, but it seems like it would be smart to secure Bitcoin for absolutely anything.

I understand that there is <5% chance that any of this will happen. I was having this conversation with someone, and I said there is a way to bypass practically any regulation, and this is what they said:


I cannot confirm whether they work in IT, but what are your thoughts on this?

There are no transactions from wallets to wallets, there are only adresses. Wallets are just methods for managing addresses and their private keys. The network does not distinguish between hardware wallets or paper wallets or "online" wallets.

To make a transaction, you need it to reach the Bitcoin network - you can be as creative as you want here, even by sending a pigeon with a QR code to a guy that has Internet and can submit the transaction. But your counterparty must have a way to verify that the transaction was confirmed - otherwise the idea of "offline" transactions won't really work, it would be way too easy to scam people.

I agree with this 100%. I am not worried about Bitcoin because I will continue to learn how to use it. I don’t care if it’s worth $100 on an exchange. I believe Bitcoin is real money. I just like to have answers other than “oh, that’ll never happen”, because shit happens. I do not trust the government, and I do not believe a manufactured civil war is beyond the realm of possibility.

I’m thinking about how we will keep Bitcoin going if some apocalyptic event does happen. I believe this is important- just in case. If Bitcoin is to survive for a thousand years, then it must outlive governments.

Okay, I've done a bit more research about this tweet.

It seems we overcomplicated things (with offline transaction signing, etc.) because unless I'm mistaken what actually happened was pretty simple: Some guy sent another guy his private key over shortwave radio.

Details here (see explanation by "nowitsalllgone"): https://www.reddit.com/r/Bitcoin/comments/aq1f99/bitcoin_transferred_via_radio_waves

So, to answer OP's above question: No, in this example the Bitcoin network was not interacted with during the transmission. However, once the recipient got the private key they did interact with the network by immediately "sweeping" the funds (to prevent the sender from spending them again).

I can not provide an argument in favor or Bitcoin when there are other assets in favor under your mentioned circumstances, we have to be realistic.  Bitcoin is digital money, so without digital there is no Bitcoin.

There have been several attempts to create a physical version of Bitcoin.  Casascius coins were among the first, but do you see it realistically happening?  Would you accept a small brass coin that supposedly has a Bitcoin private key printed on its back containing 0.5 Bitcoins that you can not check or move considering there is no Internet connection?  Do you trust the way Casascius generated, printed and disposed of these private keys?

There was another attempt last year I think, there was a company trying to produce Bitcoin banknotes that are close to impossible to replicate and you could supposedly move around Bitcoins.  But to me, that is still not safe.  It is a central institution producing these notes, so who the hell knows what could happen when the Internet is off.  For what is worth, they could be running away to a country that still has active Internet connection and steal everyone's funds off the notes.

I think almost all of us have this somehow wrong (in my opinion) belief that just because today we have a 'safe and secure' regime tomorrow will be a safe day too.  History teaches us tomorrow could be the opposite of what today was for some people or countries.

This Internet Blackout is one scenario I can not call unrealistic due to a variety of reasons.  We are constantly being told solar explosions could lead to such events.  We have a ton of examples of regimes turning wrong along the thousands of years of history.  And there is more to it.  It may seem and maybe even be close to impossible NOW, as we speak, but things could immediately change.  And there are some things we can not have control over.  I can not agree more with you however that in case a solar explosion knocks out electricity or the regime changes to one of a nightmare, Bitcoin is going to be our last priority.

How do you make sure that Washington's mesh network is running the same chain Florida's is?  In case they mine blocks separately and they collide at some point when the Internet is back up, is it not extremely insecure especially against double spending?  If the internet shuts down and I have 1 Bitcoin in my wallet, can I not double spend it by spending it once in Florida and then moving to Washington and spending it a second time?  If the two mesh networks do not communicate, there is no way Washington's has the information that my 1 Bitcoin have already been spent before.

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Regards,
PrivacyG