Post
Topic
Board Bitcoin Discussion
Re: Double Spending - How To?
by
shorena
on 01/10/2015, 10:51:14 UTC
To keep this simple, let's assume I am using a wallet like Bitcoin Wallet by Bitcoin Wallet developers on an Android smartphone. I go into a coffee shop and buy using my bitcoin wallet. I understand that it is going to take about 5 to 10 minutes before the transaction is first registered on the Blockchain.

How can I then "double spend" my bitcoin?

You just can't. Satoshi Nakomoto took care of this. You may try though, but there were no successful double-spend in the whole history of BTC as far as I know.
There was one, you may have missed it: https://bitcointalk.org/index.php?topic=152348.0 and several double spends have happened when sellers gave the goods before at least 2 confs

This the exact reason why I put a "what do we understand as double spend here" in my longer post above. A double spend on a confirmed transaction is almost impossible and only possible at all if you can either pull off an >50% attack or if the block (or even blocks) the confirmed the TX was orphaned for some reason (e.g. durring a fork).

This is even rarer than the unconfirmed double spend I think OP refers to.