First Bitcoin, then Blockstream Satellite. How about we go fully decentralized?

[pooya87]

Nationwide blackout, well, maybe in the 3rd world, or under authoritarian rule, but in the west, and a lot of europe, not gonna happen.

I wouldn't be so sure about that. Things in 1st world countries are hunky dory as long as everything is going according to expectations, otherwise one thing goes wrong and everything starts crumbling. The 2008 economy crisis, 2019 COVID, etc are examples. Just recently UK is experiencing a fuel crisis and is starting to look more like Lebanon minus the power outage (so far)!

[kano]

Nationwide blackout, well, maybe in the 3rd world, or under authoritarian rule, but in the west, and a lot of europe, not gonna happen.

I wouldn't be so sure about that. Things in 1st world countries are hunky dory as long as everything is going according to expectations, otherwise one thing goes wrong and everything starts crumbling. The 2008 economy crisis, 2019 COVID, etc are examples. Just recently UK is experiencing a fuel crisis and is starting to look more like Lebanon minus the power outage (so far)!

As I pointed out ... you've left out including asteroids destroying the earth ...

The end of the world is coming, run for your lives ... hmm I think too many people have been bored and watching too many movies ...

[DaveF]

... Just recently UK is experiencing a fuel crisis and is starting to look more like Lebanon minus the power outage (so far)!

The UK is experiencing fuel delivery issues mostly because brexit forced 1/3 of their truck drivers out of the country.
You don't get to pass a law that makes it difficult / impossible to have enough workers to do something and then complain when it does not get done.

It's not like stacking boxes, there are strict requirements and training to haul fuel. It's not like you can just grab anyone off the street to do it.

-Dave

[pooya87]

As I pointed out ... you've left out including asteroids destroying the earth ...
I think too many people have been bored and watching too many movies

Well I used real events that have happened and are happening in real world while you used an example of an event that has a minuscule chance of happening and only happens in movies...

The UK is experiencing fuel delivery issues mostly because brexit forced 1/3 of their truck drivers out of the country.

True, but the reason for it is not important, last month 3 million homes in same UK were dark. Even the example being UK wasn't important. For weeks parts of Louisiana (1.2 million homes) remained dark in the past month. Currently China seems to be experiencing a lot of power cuts. And a lot more...
The point was that power outages (and other disasters) happens everywhere, whether due to natural disasters or incompetency. Imagining some countries are safe just because some ranking calls them first world is naive.

Which is why the topic started here is a very important one that needs to be discussed and we should find a good solution before the disaster happens on a bigger scale.

[o_e_l_e_o]

True, but the reason for it is not important, last month 3 million homes in same UK were dark. Even the example being UK wasn't important. For weeks parts of Louisiana (1.2 million homes) remained dark in the past month. Currently China seems to be experiencing a lot of power cuts. And a lot more...

In any of these situations with homes losing power, did they also lose internet connectivity via cellular or satellite signals?

If people still have cellular or satellite connectivity, then bitcoin can still function just fine. They can use their phones to make transactions and run light wallets, and charge up from power banks, solar panels, batteries, whatever. If people lose all internet connectivity, then bitcoin is probably far very down on their list of things they are concerned about. Almost everyone will be more interested in re-establishing wider internet connectivity (which will obviously include bitcoin) for things like communication and managing supply chains than they would about setting up some mesh network which is only designed to allow bitcoin to work.

[mauumann]

Why not making it analogical? Give it a phisical, material form.
Some ways of doing that are opendimes and paper-wallets. It's not like the internet is gonna offline forever, so would just need to use the latter as a kind of 'paper currency' with the coverage in bitcoin while things dont go back to normal.

[o_e_l_e_o]

Some ways of doing that are opendimes and paper-wallets. It's not like the internet is gonna offline forever, so would just need to use the latter as a kind of 'paper currency' with the coverage in bitcoin while things dont go back to normal.

There are two main problems with that; verification and trust.

If I hand you a paper wallet, you have no way of verifying the balance of the paper wallet is what I say it is without access to a synced node. Without internet access, you are going to need a mesh network or blockstream satellite as discussed previously in this thread. You also have absolutely no way of knowing if I have retained a copy of the paper wallet or the private key for myself, or maybe I've handed out the same paper wallet to five other people, none of whom have been able to spend it in the meantime since the internet is inaccessible.

Opendimes would solve the problem of trust (provided you trust that Opendimes are reliable and the company which produces them are honest), but they don't solve the verification problem. Without access to a node or a block explorer, then you cannot verify the balance of the Opendime. Perhaps if I had loaded up my Opendimes well before we collectively lost internet access you could check the balances on your node which is no longer synced with the network but was synced beyond the block which contained my deposit transactions. Either way, its an imperfect solution.

[DaveF]

...Opendimes would solve the problem of trust (provided you trust that Opendimes are reliable and the company which produces them are honest)...

I can say that they are honest and legit.
I had one die with funds on it. Sent it to them, they did their magic and sent the funds to an address I provided.
No issues at all. They could have said sorry can't help you.
They could have said it's not repairable and sat on the private key for years and then swept it.
But, they just got it working and sent me the BTC

A bit OT, but still a thought. The OpenDime that is on my keyring getting knocked around for YEARS still reads with no issue.
The one that died was in an anti-static bag and 100% untouched except for the one time it was put into a PC to get the address to load it.
All electronics can die, don't store anything in a product like an OpenDime you cannot afford to loose, since if they had not been able to repair it I would have lost the funds.
Had they gone out of business I may have had to pay an independent circuit board repair place more then the value of the BTC that was on it.

-Dave

[BlackHatCoiner]

I can say that they are honest and legit.
I had one die with funds on it. Sent it to them, they did their magic and sent the funds to an address I provided.

This is definitely an invalid argument.

Their reputation is worth (probably) a lot more than your lost money. Same applies to every other custodial services. Just because they didn't cheat you on many of your deposits doesn't mean they won't. If they're anonymous, the more the money you've deposited, the more they're incentivized to steal them.

[PrimeNumber7]

True, but the reason for it is not important, last month 3 million homes in same UK were dark. Even the example being UK wasn't important. For weeks parts of Louisiana (1.2 million homes) remained dark in the past month. Currently China seems to be experiencing a lot of power cuts. And a lot more...

In any of these situations with homes losing power, did they also lose internet connectivity via cellular or satellite signals?

If people still have cellular or satellite connectivity, then bitcoin can still function just fine. They can use their phones to make transactions and run light wallets, and charge up from power banks, solar panels, batteries, whatever. If people lose all internet connectivity, then bitcoin is probably far very down on their list of things they are concerned about. Almost everyone will be more interested in re-establishing wider internet connectivity (which will obviously include bitcoin) for things like communication and managing supply chains than they would about setting up some mesh network which is only designed to allow bitcoin to work.

Another point that I would make would be:
If Alice and Bob both have internet access, if Alice wants to buy fuel from Bob, it is very easy for Bob to know with certainty if a transaction has been confirmed, and if the transaction has been well propagated throughout the network. Bob can do this in two ways, he can connect to a diverse set of nodes that is random, and is unknown to Alice, and he can also use one or more offsite nodes he controls in a geographically diverse area that is also well connected.

If Bob only has access to a mesh network, Alice will know exactly which nodes he is connected to based on their location. He does not really have any way of knowing if the transaction made its way through the mesh network to the on-ramp to the internet and into the bitcoin network and if the transaction has been well propagated (if the transaction is valid, but contains low fees based on the current fee market, it may not propagate). This makes it very difficult for Bob to assess if he can safely accept Alice's transaction. If Bob discloses to Alice prior to the transaction that he will need to wait for 10 or 20 confirmations before accepting the transaction, Alice will probably not be interested in paying with bitcoin.

[DaveF]

I can say that they are honest and legit.
I had one die with funds on it. Sent it to them, they did their magic and sent the funds to an address I provided.

This is definitely an invalid argument.

Their reputation is worth (probably) a lot more than your lost money. Same applies to every other custodial services. Just because they didn't cheat you on many of your deposits doesn't mean they won't. If they're anonymous, the more the money you've deposited, the more they're incentivized to steal them.

It's not a custodial service. It's a hardware usb dongle with an address on it. They didn't have to fix it. They didn't have to fix it for free.
It's just good customer service. It's open source. https://github.com/opendime/opendime

Anyway, back OT.
It still falls back to the fact that no matter what Alice and Bob are doing in a trade, or how they have access it comes back to the world is more then Alice and Bob.
If Alice and the rest of the world has good internet and Bob does not, Bob can come up with all these convoluted ways to get his BTC to Alice. And Alice can spend it how she likes with the rest of the connected world. If we are in the situation of where nobody has good internet since the world has collapsed. Then BTC / crypto / your credit cards / your cash / your gold and silver is all going to we worthless anyway. There is so much tech everywhere, that if it stops working for and extended period of time most of the world is going to collapse.

Having a good plan to make sure you can spend you BTC if you happen to be living in a cabin in the woods with no internet is good, if that happens to be your choice.
But if we are in a tech collapse situation, then it's not going to matter.

-Dave

[NeuroticFish]

Opendimes would solve the problem of trust (provided you trust that Opendimes are reliable and the company which produces them are honest), but they don't solve the verification problem.

I agree on the verification problem.

I don't agree on the trust problem. I don't think that we should trust that much any entity. After all, this is what Bitcoin is about: trust only math and yourself.
Maybe I'm a bit paranoid/over-zealous, but I think that you can understand my point. If they have the private keys "somewhere safe" and nobody can really complain about them (no internet for most), what stops them "claim" some of that money (if they do have access to internet)?

The final conclusion is the same:

Either way, its an imperfect solution.

[o_e_l_e_o]

If Bob discloses to Alice prior to the transaction that he will need to wait for 10 or 20 confirmations before accepting the transaction, Alice will probably not be interested in paying with bitcoin.

I agree with everything else you have written, but can you elaborate on why Bob would require 10 or 20 confirmations in such a case? I'm not sure I follow your reasoning.

Lets say Bob does not know if Alice's transaction has propagated through the mesh network, does not know if it pays a reasonable fee, does not know if it has been propagated through the main bitcoin network, and does not know its position in the mempool (and also does not know if there are any competing double spends or other issues). All that becomes significantly less important after 1 confirmation, since that is proof of good propagation and reasonable fees. After a handful of confirmations, it would be just as secure as any other transaction, no? Why is Bob waiting for 20 confirmations in this case? What additional security is he gaining from waiting for 20 rather than for 6? Are you assuming that Alice knows all the nodes Bob is connected to, all those nodes are malicious, and all those nodes are colluding with Alice?

If they have the private keys "somewhere safe" and nobody can really complain about them (no internet for most), what stops them "claim" some of that money (if they do have access to internet)?

They don't, or at least, they claim that they don't. Opendimes are provided to the customer without any private key, and you must feed it 256 bits of data before you can first use it. The Opendime concatenates those 256 bits with a 128 bit serial number and a 32 bit nonce, before double hashing with SHA256 to generate a private key. Once you have unsealed an Opendime, you can verify that the private key was indeed produced this way (provided you know the 256 bits of data it was fed by the initial owner). You can read this here: https://opendime.com/faq#provability

Having said all that, I'm sure that it is a very small number of Opendimes which are checked by the end user, so they could still be releasing some with a private key known to them and just hoping that those ones aren't checked. It's unlikely, but possible.

[PrimeNumber7]

If Bob discloses to Alice prior to the transaction that he will need to wait for 10 or 20 confirmations before accepting the transaction, Alice will probably not be interested in paying with bitcoin.

I agree with everything else you have written, but can you elaborate on why Bob would require 10 or 20 confirmations in such a case? I'm not sure I follow your reasoning.

Lets say Bob does not know if Alice's transaction has propagated through the mesh network, does not know if it pays a reasonable fee, does not know if it has been propagated through the main bitcoin network, and does not know its position in the mempool (and also does not know if there are any competing double spends or other issues). All that becomes significantly less important after 1 confirmation, since that is proof of good propagation and reasonable fees. After a handful of confirmations, it would be just as secure as any other transaction, no? Why is Bob waiting for 20 confirmations in this case? What additional security is he gaining from waiting for 20 rather than for 6? Are you assuming that Alice knows all the nodes Bob is connected to, all those nodes are malicious, and all those nodes are colluding with Alice?

The security of n confirmations relies on the assumption that you are not being subjected to a sybil attack. If your transaction has 6 confirmations on the actual chain with the most total work, unless the attacker controls 51% of the network hashrate, the transaction for all intents and purposes is not going to get double-spent. However, if you are connected to a single malicious node that sends you 6 blocks that in sub reflect a transaction having 6 confirmations if these 6 blocks do not reflect the sum total of the most total work, your transaction could already be double-spent.

If your node was previously connected to the internet, and you know you were not being subjected to a sybil attack because your node was connected to a diverse set of nodes, you can be reasonably certain you are not being subjected to a sybil if you immediately start receiving blocks every approximately 10 minutes. However, in an event as described in the OP, it is likely that many of the miners are likely to be without power, so it is likely the average block time will be well above one every 10 minutes, and therefore it will be difficult to know if you are being subjected to a sybil. The cost of serving n blocks to someone while executing a sybil is approximately the expected mining revenue of generating n blocks, so the additional security from asking for 10 confirmations over 6 confirmations is that any sybil attack would be more expensive to execute.

You might argue that Alice is only one person buying a few hundred dollars worth of supplies. However, it would be possible to execute a sybil attack on a large geographic area, and it would be possible that Alice was part of a larger syndicate of organized crime that is taking advantage of the current situation.

[BlackHatCoiner]

The cost of serving n blocks to someone while executing a sybil is approximately the expected mining revenue of generating n blocks, so the additional security from asking for 10 confirmations over 6 confirmations is that any sybil attack would be more expensive to execute.

Aren't you find your sayings a little paranoid? Alright, let's assume that Alice has been encircled from dishonest nodes who're ran by the attacker. In order for the attacker to make those 6 confirmations look like they've come from the honest miners, they have to gain access to a LOT of computational power.

For instance, if each block is generated every 10 minutes averagely and they want to make it look like a bad-luck scenario (100 minutes each block) instead of an obvious sybil attack, they still need to accumulate a 10% of the total hash rate.

And note that there's no way for the attacker to be 100% sure that Alice is connected only to dishonest nodes, other than compromising her computer. And I'm asking myself, who and why would wanna do this?

[PrimeNumber7]

And note that there's no way for the attacker to be 100% sure that Alice is connected only to dishonest nodes, other than compromising her computer. And I'm asking myself, who and why would wanna do this?

The scenario in the OP is that electricity and internet connectivity are both down, and that some kind of mesh network is being used to communicate transactions and found blocks. With a mesh network, an attacker physically present in the same location as his victim will know which nodes his victim is connected to because he will be connected to the same nodes.

The point I was trying to make in my last post is that in the scenario described in the OP, as someone receiving bitcoin, you really don't have a good handle on the risks involved in accepting transactions. It might not be unreasonable for 90% of miners to be offline for some time in this type of scenario, so maybe there are several days with 100-minute blocks.

IMO the more likely risk is that accepting a transaction via a mesh network with no internet connectivity is that, due to network failures, the transaction never makes it out of the mesh network, or if it does, that the transaction is not paying a sufficiently high fee that internet-connected nodes relay it. There wouldn't necessarily be malicious intent on the part of the person sending you bitcoin, but the end result would be that you would still be unable to spend your coin.

[n0nce]

So far, I think the Satoshi Radio from Brazil is the closest I can get to what I was thinking about. Will definitely research more about how it works, although I think that unless this capability of receiving/broadcasting txs is embedded into a device specifically created for offline over-the-air Bitcoin transactions, it would be useless in the events previously mentioned (how many people would use the OTA Bitcoin receiver/transmitter .. let alone the Satoshi Radio?).

Actually, a good step that anyone could do really, would be to write a piece of software for Raspberry Pi which uses a GPIO pin with an antenna to transmit in HF range and replicate what 'Satoshi Radio' built. It is illegal in most countries, but if you're allowed to, you don't care, or you just want to 'prep' and only use it with a proper antenna once there's actually a catastrophe event, you could build one and have it on the ready in case you'll need it.
If your idea gains traction and people want this as a pre-built, you will surely be able to buy some Pis, have some enclosures made and make it all look neat & sell it as a finished product. That's how many companies get a product out which is not too hard to make since they use off-the-shelf parts - like the MyNode for example.

A good place to start would be the following article.

The basis is the library piFM. With this, it is possible to “misuse” GPIO 4 (pin 7) of the Raspberry as a transmitter. An antenna (either a real antenna or a simple wire) must be connected to it.

But besides radio waves, is there no other technology using waves or something that could be used over very long distances without a necessary license/SIM card?

Well on a physical level, there are 3 main means of communication: wires, radio waves (electromagnetic waves of any kind) and light (morse alphabet for example); though light is actually an electromagnetic wave as well, just different wavelength really.

[DaveF]

Was looking for something else and found this:
https://lora-alliance.org/
Not the fastest thing out there but it will move limited amounts of data. So you could probably hack something together after the end of the world.
But, I still think it's a thought experiment only, never going to be put into live use.

-Dave