I am new to Bitcoin and making an attempt to grasp how the double-spending downside can happen and implicitly, the necessity for “mining”.
For instance Bitcoin labored the next means:
Within the community, one node is chosen because the “moderator” node. That’s, the duty of making a “block” from the broadcasted transactions lies on this block and no person else. This “moderator” node is modified each N seconds or each N block creations, and many others.
From the pool of unconfirmed transactions, the “moderator” randomly picks 100 transactions. It verifies that they’re reliable (approved) utilizing the general public keys, and it verifies that there isn’t a “double-spend” among the many chosen transactions and previous transactions by wanting on the blockchain.
As soon as it verifies that every one transactions are legit, it creates a block just by placing these transactions collectively (that’s, no mining, nothing. Merely a really quick operation) and broadcasts this block on the community.
Each node that receives the block verifies that it’s reliable. That’s, they confirm that the transactions are approved by checking the general public key and so they confirm that there isn’t any double spend both inside the new block itself, or inside the entire blockchain.
So, what’s the issue with this scheme? How can “double-spend” happen right here and the way can “mining” forestall it?