Bitcoin Forum

Let's say a massive nuclear war happens, all mining power is dead and we can't start building it again for a while. Could people run the blockchain by doing the hashes manually like this?

https://www.youtube.com/watch?v=y3dqhixzGVo

What about nodes? how do you check funds and validate transactions?

Can Bitcoin survive without computers existing?

Well technically it could work. However, take a look at:
Unless there we a emergency fix that would lower the difficulty, this would be pointless. Additionally, do you really think that someone would worry about Bitcoin mining in a 'massive nuclear war'?

If there were nodes with connections, they would still work. Technically you don't need mining for nodes to operate (albeit you won't have confirmations).

Yeah I know that in a realistic scenario this wouldn't be a worry on people's mind, im just theoretically imagining if Bitcoin could survive in a scenario where no computers are there anymore to do the calculations for you.
Also, no computers at all and no internet.. in this case I don't see it happening, even theoretically speaking.

There is no Bitcoin without the internet. Technically as soon as some people (nodes, miners) regained their connections the network could 'jump-start' again, but at this point we would only be speculating (as we can't be sure what is exactly going to happen).

Seems like I've overlooked this part; the answer is certainly no.

Yes I do agree with the comments in a scenario when no computers are there then no survival of bitcoins might show in lieu of calculations and to maintain a theoretical system and in case of bad incidents without internet it is not possible as well since it is a digital currency and can not survive without computers and internet. I would love to hear comments from others to get more information for my knowledge.

Having bitcoin survive would be the least of your problems in that scenario.

Think about food and infrastructure compeletely going down. Nobody would care about bitcoin or fiat at this point. Safety and food would be the only thing on peoples mind.

Spending time calculating hashes manually is not a priority in that case.

Untrue. Here's a practical analog p2p network implementation, as conceived by Alphonso Tourette in 1869.
http://s24.postimg.org/nrzm1jql1/canphone.jpg
While Tourette's work was far ahead of its time and the scheme failed to take hold [he was consequently arrested], many modern inventions such as the telephone operator & MLM would be impossible without his seminal contribution to distributed system architecture.

Neither Bill Gates' fortune tbh  :D

Not necessarily. You could theoretically write out a transaction on a piece of paper. You could calculate the transaction hash and the signatures by hand. Then the transactions can be sent by runners to other people who copy all of the data onto more paper and give them to more runners to give to more people and so on and so forth. If we had wires then there wouldn't need to be runners, it could be done over morse code or something similar.

In this scenario a node would be a person and the network be all of the runners going between nodes.

Of course this is entirely unfeasible as each person would have to calculate the hash of a transaction and verify the transaction by hand whenever it receives a new one and that would take ages to do.

With a massive nuclear war, the problem will not be bitcoin or blockchain. There question will be if some people will survive? And if anyone survives, why they would use money (bitcoin or fiat) ?

Well doesn't you statement agree with mine? Technically one could make it work but it would be so slow and complex that it would make zero sense to even try to keep it running (ergo answer is no). The Bitcoin network does not function without the internet and computers. Someone could try calculating, with the given hashrate in the video, how long it would take 1 man to find a block now. I would be interested in the answer.

Relevance?

For you maybe; I could care less. OP was just curious I guess and I'm sure that OP realizes that Bitcoin wouldn't matter at that point.

Brilliant i like it, mining would slow to a snails pace but at least it would keep going.......  ;)

Perhaps if we had a mesh network of wireless P2P phones (and computers, I suppose) it might keep going?

Did you even read anything? OP is asking whether it can survive without computers of any kind.

We'll have bigger fish to fry at that point. Maybe there'll be some bored people in bunkers who can do it as a hobby to pass the time.

But without a way to connect with other bunkers it would just be pointless don't you think?

The lowest Bitcoin network difficulty is 1.

For difficulty 1 it takes about 2**32 hashes to solve one block on average.

So about 4295 million hashes on average to solve a block at the lowest possible difficulty.

If you can do one hash a second and work 24 hours a day you would take about 136 years to solve a block on average.

Waiting for a confirmation could be a slow process.

(This totally ignores how many difficulty changes it requires to get the difficulty back to 1.  Current difficulty is 184326601357.  If it halved each difficulty change, it would take 38 changes. Each change would take 4 weeks. So Bitcoin would take say 3 to 4 years of carefully controlled difficulty drops to get to a difficulty of 1.).

Ref https://en.bitcoin.it/wiki/Difficulty#What_network_hash_rate_results_in_a_given_difficulty.3F

machines have a far better chance at surviving a nuclear war then you pathetic humans

http://www.innoros.ru/sites/default/files/news/images/air_skaynet_0.jpg?1383217201

I think if humans could survive then along with manual mining (which requires calculation) the people could use "Semi"-Manual mining that involves the use of Calculators (that use small solar panels) or Smartphones (if they survive).

and how would the people living in far places mine the same block ? As currently whoever mines first gets first.

You should also consider that a nuclear war, would also destroy the economy and also equipment used to print money and also banks. {Private ledgers} So the alternative for Bitcoin would also suffer

the same consequences. A Post nuclear world, would be a world where people would have to go back to the bartering system... where you trade canned food for clean water for instance. Most people

will have to deal with survival issues ... { Radiation pollution & contaminated water and food and the medical issues that goes with that... and later cancer and birth problems }  ??? ...Bitcoin will still

run unaffected, in countries not hit by this attack. 

Wouldn't one guy with a PC which has survived, be easily able to execute a 51% attack?
The high hashing power which secures the blockchain is what makes Bitcoin what it is today.

At this stage i dont think bitcoin could survice in a nuclear war with the help of manual hashing  ::)
Other problems are way bigger.

Bitcoin needs internet to work. As most of the computers, and therefore their interconnection i.e the internet, would get destroyed then it would be of no use if some people with PCs survive. If the servers of Bitcoin or other cryptocurrencies would not survive then their value would become zero !

In case of global catastrophe. Mass internet fail due to  cosmic rays, emp, nuclear war other problems. BTC will the least of our problems.
Lets be realistic here. Bitcoin is digital currency, manual mining was just showcase that something like this potentially can be conducted.
For bitcoin to work we need fully computerized mining, network with nodes.