What is a node ? (Investopedia - How to set up a node) How many nodes there are ? (Google) There are three more types of lower amount* Cloud, public, etc. How many do you need to manipulate the coin ? (https://101blockchains.com/disadvantages-of-blockchain/) In 2021 it would have taken around ~70 000 nodes(computers), to control the Bitcoin. That's roughly $1Billion in expenses. How many of Wallst players could afford that ? Basically, - any bank/hedge fund/ or well known entrepreneur/investor.
Ah! This is why every crypto acolyte runs a node or ask others to run it. To guarantee independent nodes and network immutability. Interesting.
Correction for everyone, this is not how the Bitcoin network works There are 100,000 Bitcoin core honest nodes (many are not visible as in order to be visible, you'll have to punch a hole in your router to allow incoming TCP port 8333 connections to your Bitcoin Core honest node) Even if you have 1,000,000,000 Bitcoin core dishonest nodes distributed across the world, it would not matter All the Bitcoin users running the correct version of the Bitcoin Core protocol will ignore all malicious nodes if they try to pass incorrect data -------------------------- Nobert, I'm assuming you jumped on this conclusion yourself and started a thread? Not even the biggest critics of Bitcoin have produced an article on this type of Bitcoin attack ------------------------- The valid attack is to 51% attack the Bitcoin mining hash, which does have a $ value that keeps increasing, and this is only valid for new Bitcoin blocks and does not affect existing 19 Million Bitcoins, but that's a different topic and is no longer a concern since China banned Bitcoin mining
LOL this thread is so cute. Taken from an article of Coindesk: Likelihood of a 51% attack As a blockchain network grows and acquires news mining nodes it makes the chances of a 51% attack taking place less likely. That is because the cost of performing a 51% attack rises in tandem with the network hashrate (the amount of computational power committed to the network). Essentially, the bigger the network and the more nodes there are participating in it, the more hash power is needed to control over 50% of it. But even if an attacker were to reach above 50% of the hashrate, the size of a blockchain could still provide security. Because blocks are linked together in the chain, a block can be altered only if all subsequently confirmed blocks are eliminated. While possible, doing so would be incredibly costly for the attacker for two reasons: The attacker would have to expend great amounts of computing power (cost of electricity) to achieve a 51% hashrate, particularly on larger more established networks Because the miner is not acting in a way that participates appropriately, they would no longer be receiving the blockchain rewards that come with mining Thus, the more significant number of transactions there are, the more blocks are on the chain and the more difficult it is to alter a block. While the threat of a 51% attack still exists (albeit extremely unlikely) on big blockchains like Bitcoin, the financial costs would far outweigh the benefits. Even if an attacker were to expend all of its resources to attack a blockchain, the constant addition of blocks to the chain would give only a relatively small window to a number of transactions for the attacker to alter. Sorry bud, but no one is going to spend over a billion for a small limited attack that wouldn't even do much damage.
how will the network know bad node from good one. For example let’s say you and I partner and start mining. Will our node be good or bad? How will it be determined?
Apparent cost of the 51% attack for various coins. https://www.crypto51.app/ Why would they list the cost of the attack if it wasn't possible? Dunno, strange
Boom!! It's built into the software code for checks and verification You can run a node and open up the logs and you'll see your node banning specific IP's as it detects "bad" network information This is at the heart of how Bitcoin revolutionized the world when it provided a solution to the Byzantine General's problem ----------------------- If you do not run a full node, you're relying on others to provide the truth to you which most of the time are ok, think Electrum wallets relying on public Electrum servers This is one of the criticisms of the Ethereum network as hardly anyone runs a full node (including me) and when the Metamask wallet started blocking Russian transactions, they did so by blocking it on the Infuria server infrastructure and incorrectly blocked Venezuela for about a day ------------------------ Byzantine General's problem https://bitcoin.org/bitcoin.pdf