Bitcoin Forum

Today I read some online article about dangers Bitcoin can encounter and this problem caught my eye:

The Chinese firewall or another Internet issue causes the global Bitcoin network to be split for a few days.

"The Chinese have a fantastically large firewall that they can use to block Internet traffic," says Hudson. If the firewall caused the Chinese miners to be disconnected from the global Bitcoin network for a few days, during that time, the Chinese miners would still continue to mine the transactions taking place within China, while the rest of the network would be mining a totally different set of transactions. “Realistically, that would look like a fairly irreconcilable fork,” says Hudson. “There’s no mechanism to bring them back together again short of one winning and the other losing completely.”

In general, the system only works well as long as the vast majority of the mining hardware is online and a large percentage of the miners follow the same set of rules. So basic Internet connectivity issues and “forks” that occur when different miners run different versions of the software could also cause a drop in the value of the currency.

More at:http://www.forbes.com/sites/laurashin/2015/12/28/should-you-invest-in-bitcoin-10-arguments-against-as-of-december-2015/ (http://www.forbes.com/sites/laurashin/2015/12/28/should-you-invest-in-bitcoin-10-arguments-against-as-of-december-2015/)

Is this real issue and problem?

I'm not an expert on the Great Firewall of China, but if Bitcoin connections were entirely blocked, nodes and miners within China probably wouldn't even be able to connect to each other. They'd be completely out of the network. But let's assume Chineses miners would start running a fork of their own... Mining would probably come to a halt until they could connect through other means. A fork of their own would damage the integrity of the network and that's what miners rely on for profits, and profits cannot stop. Damaging Bitcoin would be a shot in their own feet...

i don't see a problem, if not for chinese only, because at that point, it will be like they are mining on their own version of bitcoin, which would be an altcoin accepted only in china

the other would continue to mine the real bitcoin accepted in every other part of the world, the network would lose 60% of hashpower though

and even if this will bring bitcoin price down, the diff will be also cut by a great %, so everything will be levelled, out, bitcoin netowork is self sustained

If the Chinese miners have 60% of the hashing power, then their chain will be longest, and the other will be abandoned when (not if) the Bitcoin network gets connected again.

In practice, what would happen is that someone would notice the isolation pretty quickly, and steps would be taken to connect through the firewall. With more web traffic going HTTPS instead HTTP, one path of keeping China in the Bitcoin network would be to tunnel it over HTTPS, which is nearly impossible to detect.

If the Chinese firewall blocked all Bitcoin traffic, then people in the China couldn't send their coins to Western exchanges and do anything with them. If all Bitcoin traffic was blocked by the firewall, then any connections to Western exchanges would also be blocked.

Coins from China couldn't be spent anywhere but China, and coins from the West couldn't be spent inside China. If the firewall block was removed and there were two separate chains they could be merged without many problems because the firewall would have prevented double spends.

It's an interesting idea, but I'm not sure china would want to block Bitcoin. They might block web pages, but that shouldn't affect Bitcoin. China needs international trade, and to unload its dollars, Bitcoin will help them do this.

if china blocked the port bitcoin talks on.. they cant mine, relay, transact.. or anything else.. because they are blocked.. not just from europe or america but from themselves..

thats right they cant even relay to each other.. thus there would be no new chain as data cant be relayed..

if it can be relayed then, obviously they are not blocked and so there is no problem

We can imagine that the Chinese government could block all data BTC-related, but we need to go further and imagine what Chinese miners would do after that. I guess some would try to move their equipment to Australia. Some others may simply switch off their computers waiting for the government to remove its firewall. There are several options...

Well if this is the case, it seems whoever wrote this article doesn't understand how the protocol works... I was worried for a second so thanks. It seems only the chinese would lose thanks to their stupid goverment.

Great Firewall ... is only a BIG SHITED LIST on ISP.
In France, we have the same dumbed solution.

It's crazy how these providers have so much control.

The GFC is quite sophisticated and certainly capable of determining whether a connection is exiting the country or not.
If it was their intention to block that kind of bitcoin connection, then there would be 2 chains resulting.

Offhand, I can't see why they would choose that approach rather than blocking all bitcoin connections. Guessing the kinds of things these censoring governments choose to block is a crap shoot tho.

If they decided to 'block bitcoin' everywhere, the first thing would be a block on the known ports used for all connections. That would probably be supported with deep packet inspection to detect simple port changes.
We know they have this kind of inspection in place for Tor ports, for example.
The way around that is to encrypt those connections asap.

Why would China want to block "internet trafic"? Most of the Bitcoin users in China are only miners. The Chinese don't really use Bitcoin. If China did do this, it would be no good for them.
They will not do this.
It is for their own good, and for the good of everyone else in the world.

The Great Firewall would need to block all VPN and SSH traffic too. I would imagine Chinese mining farms could easily set up a node in nearby HK and access it from China via an encrypted connection for mining purposes. I doubt the firewall would block router-to-router IPsec traffic between a Chinese company and its HK branch office.

It won't be a real issue unless the bandwidth requirements of the network grow beyond the capabilities of free services like Tor.

provider should die, like the bank, they are another centralized aspect of our system, a kind of mesh network should take its place, so we can have a truly decentralized internet, without "big node" that control everything

it would have some security issues though

I have enjoyed reading the article, but I think it calls for security concerns

I bet the big miners have already a large system of redundancy to protect their connections at all costs. Multiple VPNs and stuff like that to ensure they can keep going at all times.

Besides the cooling for the miners, a good internet connection is one of the most vital things for these farms. No way they would let a government firewall block this.

All that would be required is for one node to push the block outside the GFW.         This is 1MB or less roughly once every ten minutes that we are talking about.    This can be done via dialup, or satellite, or whatever, if needed.   Obviously at least one mining organization would want to ensure their blocks are getting out and that they aren't wasting hashes mining a chain that isn't the longest chain -- and thus have an incentive to take "extreme measures" if needed to remain connected.

I don't think fixing internet access is so simple as removing internet providers from the picture. Having then is not ideal but removing their services could potentially do more harm than good.
Not to mention it is impossible as of now when internet structure is not even close to being able to function without data centers and centralized services.

For now, we are trapped inside the current mode, but in the future, long term, like 10 or 20 years, meshnet technology should be able to deliver a totally decentralized internet, which will be the end of internet censorship, and Bitcoin will be the king currency of this new internet, surpassing all other forms of money ever.

I'm not sure if a mining node must physically exists in china

Take pooled mining for example, you can setup the mining pool server outside of china, and just dispatch mining jobs to large mining farms in china and get result back, no need to send any bitcoin transactions in the communication, so the amount of data involved is only a little for stratum protocol

https://mining.bitcoin.cz/help/#!/manual/stratum-protocol#why (https://mining.bitcoin.cz/help/#!/manual/stratum-protocol#why)

I think the reason that chinese mining pools do not want to locate their servers outside of china is more of a security aspect that they don't trust a 3rd party outside china to maintain their server which handles large financial transactions. But if Chinese government start to crack down on bitcoin traffic in china then they have to move all the pool server outside of china but mining operation can still remain in China

Correct me if I'm wrong since I have not run any mining pool