However, it still has a vulnerability that can be exploited.
It is not a vulnerability. This is the protocol design.
It aims to make it extremely hard to achieve and being extremely unprofitable.
Financial Incentives excluded.
When I make a transaction that transfers 100 Bitcoin to a Lamborghini company wallet, the transaction is encrypted and put into a place called "unconfirmed transactions".
It is not encrypted, it is signed.
And it is not put into a place called "unconfirmed transactions", it is an unconfirmed transaction in the mempool of the nodes until it is being included into a block.
Not yet, the transaction in this block will be publicized and should be verified by other miners. If there is more than 50% validation, this block will be shown on the blockchain and the transaction will be recorded in the ledger. I officially completed a 100 Bitcoin transfer to buy a Lamborghini.
If the transaction is valid, it is being included. Otherwise not.
There is no 50% mark or anything similar.
Every node which thinks this transaction is valid, will add the block including it to the chain.
The other ones don't.
If - for whatever reason - 50% of the network thinks a block is invalid, while the other half thinks its valid, a fork happens.
But since there is a consensus on which transactions are valid / invalid, this shouldn't happen.
Especially with Bitcoin, the world's largest cryptocurrency. Experts believe that Bitcoin can never be affected by a 51% attack.
[...]
In addition, experts also speculate that a small blockchain of an altcoin (not Bitcoin) can be attacked 51% entirely. Because attacking small blockchain requires less computing power than attacking Bitcoin. That's why we often see other crypto coins being attacked 51%, but Bitcoin has never been so.
Bitcoin already had a 51% attack.
It was in the very beginning when nearly no one was mining.
Nowadays, i agree. It is effectively not possible anymore.