What Does Double Spending Mean?
Let’s consider this example:
You go to Starbucks and order a cappuccino worth $10. You pay in cash. Now that $10 in cash is in the cash vault of Starbucks. By all means, you simply cannot spend the same $10 somewhere else to make another purchase.
Unless you steal it…!!!
As you paid with your $10 bill, the service provider at Starbucks instantly confirmed that you have paid, and you received your coffee in exchange for the money.
But Bitcoin is digital money, not physical cash. Hence, Bitcoin transactions have a possibility of being copied and rebroadcasted. This opens up the possibility that the same BTC could be spent twice by its owner.
How?
In our Starbucks example, you paid cash, so the payment was confirmed and verified instantly by another human. But with digital currency like BTC, if this verification mechanism is missing, it can lead to double spending.
Anyone can just copy that digital money and pay somewhere else.
And here is where the unique invention lies…
Bitcoin, although being a digital currency, solves the problem of being copied and getting spent twice.
Let’s consider this example:
You go to Starbucks and order a cappuccino worth $10. You pay in cash. Now that $10 in cash is in the cash vault of Starbucks. By all means, you simply cannot spend the same $10 somewhere else to make another purchase.
Unless you steal it…!!!
As you paid with your $10 bill, the service provider at Starbucks instantly confirmed that you have paid, and you received your coffee in exchange for the money.
But Bitcoin is digital money, not physical cash. Hence, Bitcoin transactions have a possibility of being copied and rebroadcasted. This opens up the possibility that the same BTC could be spent twice by its owner.
How?
In our Starbucks example, you paid cash, so the payment was confirmed and verified instantly by another human. But with digital currency like BTC, if this verification mechanism is missing, it can lead to double spending.
Anyone can just copy that digital money and pay somewhere else.
And here is where the unique invention lies…
Bitcoin, although being a digital currency, solves the problem of being copied and getting spent twice.
From my understandings before, double spending is only possible if that someone has equal or more than 51% of the total mining power of the network? So because of that, they get to make transactions according to their will by simply spending the digital coin twice.