Can someone explain double-spending with an example?

[Sakzsee]

Hey!

I am reading the Bitcoin white paper now and I am not too sure if I understand the concept of double-spending well.

Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending.

Can someone simplify it with an example?

Thank you.

[mattjaf]

double spending is when you can spend the same dollars more than once.

Say you go to the gas station and buy a candy bar with your card and the money never gets subtracted from your account and you can buy another candy bar 1 million times with the same 1 dollar.

Imagine having a magical 100$ bill that you can spend unlimited times and you'd still have the bill in your pocket.

What that line is pretty much saying: Is that digital signatures partially solve this issue, unless you gotta trust some centralized party to prevent this from happening

[Sakzsee]

Yep, this makes sense now! Thank you.

[alymurtazamemon]

@Sakzsee

Suppose you have $10

You give it to me, now I have $10.

But if know you can send to a third-person $10, then this is double-spending because you already give that $10 to me and you have left nothing.

Bitcoin eliminates this problem, if you have already spent your amount you cannot spend it again.

Hope it clears your answer, if yes then mark it as answered.

Thanks

[Sakzsee]

Hey! Thanks for the answer.