Bitcoin Forum

Sorry for asking silly question.

Suppose i have 1 BTC in my wallet and I take a backup of it. Then i send that 1BTC so some other address and my wallet becomes empty.
And now if i restore that backup which i had taken while it was having 1BTC. Will i get duplicate BTC which i already spent?

Lol.. that would be an easy hack.

Once spent, its spent.

Then what do i get if i restore backup?

You will retain the keys to the address that had stored the funds and a transaction that shows them as spent once you sync up.

But your question is really cool..wish bitcoin has this feature for atleast one day and we will become millionaire overnight.

 ;D ;D ::)

And the next day 1000 BTC equalled 1 USD. Just one malleability has given so much trouble in price ...can u imagine where BTC will go if this ever happen :P

Its not possible.
The data about you have this much money in your wallet is in the blockchain and that blockchain is not completely under yours or anyone's control because its decentralised.
When you spent it will be there in the blockchain.

When you backup the wallet, you backed up your key to access your wallet address.

Technically, you can do it if you can do a 51% attack on bitcoin network, LOL!

Let me try to answer your question.

Bitcoins do not exist in your computer or wallet technically and they exist on blockchain which is a distributed public ledger.

First you need to understand what exactly you hold when you say you have 1 BTC in your bitcoin address. What exactly you hold is a piece of information that is only with you, that gives you ability to transfer bitcoin from that address to another bitcoin address.

So when you backup your wallet, you are basically backing up this information that gives ability to move the bitcoins from your address to another address. You are not really backing up your bitcoins itself. After backing up, if you move the bitcoins then that bitcoin is gone from the address and this transaction is recorded in the distributed public ledger.

Say now you formatted your computer and you restored that. Now even though you have the ability to move the bitcoins in that address, the bitcoins itself is not indeed there as you actually already spent it as per the public ledger.

Adding to the above in a layman style:
Wallet restoration will not give the ability to move the previous bitcoins in that address since wallet doesn't have memory about your previous coins. That information is stored in the blockchain. If you backup and restore the previous blockchain stored locally in your computer and you are not in sync with the network and did a second spent on the already spend coin, it will not be accepted by the peers when syncing is completed.

Thanks for info.

Got that.

I demand to Satoshi we need double spend feature, atleast that way Government will recognise Bitcoin as legal medium of payment and they will use it in government payments. Keep swimming.

Regards

Or a way to generate bitcoins without mining - i bet this will make govt to accpt it as a legal medium. Else fiat would not have been haha