How the Blockchain Remains Connected Even When a Fork Occurs
In Bitcoin, there is no central authority; transactions are conducted based on a peer-to-peer (P2P) system,
which relies on the transmission, exchange, and validation of information across a network based on trust between devices. Within a P2P system, the question of how to establish power dynamics within the network arises. Bitcoin, which adopts the Proof of Work (PoW) model, uses a method that grants voting power based on the amount of CPU computation performed.
The system involves solving a problem that requires massive computational effort—finding a hash value that meets specific conditions. The first miner to solve this problem is granted a block as a form of voting power and receives a reward.
However, in this system, there are extremely rare cases where two valid non-prime values exist, leading to multiple miners successfully mining at the same time. Since
separate blocks are generated, the single blockchain that has continuously recorded past transactions temporarily splits into two branches; this is called a fork.
However, the system is designed such that if the length difference between the two chains exceeds a certain threshold, the shorter chain is discarded. Since miners working
on the discarded chain will not receive any further rewards, they naturally return to the longer chain.
