PoW vs PoS (part 2)

2. What is PoW? Why is there PoW? The above article is a summary of the white-paper written by Satoshi Nakamoto about Bitcoin, the brand new and revolutionary invention that has permeated the whole world. Satoshi Nakamoto solved the aforementioned problem of the authenticity of blocks and the "forking" of blockchains with a system called Proof-of-work, which Adam Back used in his project called "Hashcash". So what is this Proof-of-work, let's examine together how it solved the above problem. Satoshi Nakamoto introduced a very simple rule for the correctness of the blockchain in the Bitcoin blockchain. This rule is the "Longest Chain" rule that I underlined above. This rule states that THE LONGER CHAIN IS THE CORRECT CHAIN. So incoming blocks should prefer the longest chain. This prevents the chain from forking.
In this case, the new block will join the malicious blocks 6 to 9. This would undermine the trustworthiness of the blockchain. Therefore, Satoshi Nakamoto introduced another rule. This is written at the top. Satoshi used CPU power as the basis for minting blocks. This CPU power is the basis of Proof-of-work. In other words, the person with more CPU power has a better chance of producing blocks than others. We call these people who generate blocks based on CPU power miners. In a blockchain where 2 miners have equal CPU power, they both have a 50%-50% chance of producing blocks. If one of the miners adds a few more devices in addition to their mining devices to mine blocks, they will have more chances to mine more blocks.
In the image above, you can see the first ASIC miners needed to mine blocks in the early days of Bitcoin. In order to mine more blocks, miners began to compete for more blocks, increasing the number of miners they had at their disposal, eventually leading to mining devices managed by huge mining companies like the one below.

In short, the so-called MINERS are the PEOPLE who ADD NEW BLOCKS to the Bitcoin blockchain knowing and acting on Satoshi's rule of let the one with more CPU power generate blocks. If there was no rule of adding blocks based on CPU power, if everyone could easily add blocks, the "follow the long chain" rule would be manipulated. Because CPU power is limited and also costly (both hardware and electricity). While we're at it, it's worth adding that if people with more CPU power can add blocks, then the question arises as to whether people who cheat can't add bad blocks when they have more CPU power. The answer to this question is yes. This is the 51% attack that almost everyone is talking about. A 51% attack is when more than 51% of the CPU power in the system is in the hands of a single malicious person. In this case, the guy with 51% or more CPU power will be able to add bad blocks to the system. It's not a fatal attack, but it seriously undermines the trust in the blockchain. We can get away with 51% attacks. However, I'm skipping this part as it will seriously lengthen this already long article. You can read a small 51% attack flood I wrote on Twitter. 🙂