It's not just mining. It's also the processing nodes. With a majority control you can take over the block chain. Which is why its security depends on its decentralization.
Sorry, I should clarify, when I say node, I'm referring to the partial or lightweight nodes, as opposed to the full nodes (miners).
And I am concerned, because at any time if some entity controls the majority of the nodes they can completely manipulate and even crash the currency by creating false transactions and verifying it by majority consensus. And the vast majority of bitcoin and nodes are held in China (or were the last time I looked into it a few years back), which has a potential for very bad things to happen to bitcoin, given the CCP's history with currency.
This is infeasible. All transactions have an origin and a destination address. To transfer bitcoins out of the origin address you need to know the private key for that address. If you don't have that private key, it'd take thousands of years to guess it, even if you had the combined computing power of every computer on Earth.
Due to asymmetric cryptography, it's very easy for anyone to verify whether or not a transaction is legitimate.
verifying it by majority consensus
The whole system is designed in such a way that you can't just make up transactions and verify fake ones. Those blocks would immediately be rejected as invalid by everyone else.
The whole verification by consensus happens when 2 different miners solve the same block at about the same time. The blockchain forks and whichever side of the fork grows larger in a shorter amount of time becomes the accepted path, and the other side fades away as if it never happened.
But each block must be filled with valid transactions for it to be considered legitimate.
The whole system is designed in such a way that you can't just make up transactions and verify fake ones. Those blocks would immediately be rejected as invalid by everyone else.
Which only matters if "everyone else" is the majority. In this case, "everyone else" is the minority if China's bitcoin investment is coordinated. It's called the "Byzantine Generals Problem" and is the basis for all validation on a P2P network. It is not impervious to attacks, and China is situated pretty well to be able to carry it out.
Either way, just as there is no guarantee of security, there is also no guarantee of threat, and everyone is free to put their money wherever they like.
It's not just mining. It's also the processing nodes. With a majority control you can take over the block chain. Which is why its security depends on its decentralization.
https://en.wikipedia.org/wiki/Byzantine_fault
Miners ARE the processing nodes.
I'm not concerned about China having the most miners, because at any time anyone can become a miner.
Sorry, I should clarify, when I say node, I'm referring to the partial or lightweight nodes, as opposed to the full nodes (miners).
And I am concerned, because at any time if some entity controls the majority of the nodes they can completely manipulate and even crash the currency by creating false transactions and verifying it by majority consensus. And the vast majority of bitcoin and nodes are held in China (or were the last time I looked into it a few years back), which has a potential for very bad things to happen to bitcoin, given the CCP's history with currency.
This is infeasible. All transactions have an origin and a destination address. To transfer bitcoins out of the origin address you need to know the private key for that address. If you don't have that private key, it'd take thousands of years to guess it, even if you had the combined computing power of every computer on Earth.
Due to asymmetric cryptography, it's very easy for anyone to verify whether or not a transaction is legitimate.
The whole system is designed in such a way that you can't just make up transactions and verify fake ones. Those blocks would immediately be rejected as invalid by everyone else.
The whole verification by consensus happens when 2 different miners solve the same block at about the same time. The blockchain forks and whichever side of the fork grows larger in a shorter amount of time becomes the accepted path, and the other side fades away as if it never happened.
But each block must be filled with valid transactions for it to be considered legitimate.
Which only matters if "everyone else" is the majority. In this case, "everyone else" is the minority if China's bitcoin investment is coordinated. It's called the "Byzantine Generals Problem" and is the basis for all validation on a P2P network. It is not impervious to attacks, and China is situated pretty well to be able to carry it out.
Either way, just as there is no guarantee of security, there is also no guarantee of threat, and everyone is free to put their money wherever they like.