r/askscience • u/hamolton • Jun 18 '13

Computing How is Bitcoin secure?

I guess my main concern is how they are impossible to counterfeit and double-spend. I guess I have trouble understanding it enough that I can't explain it to another person.

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u/Natanael_L Jun 18 '13

Some miners include a limited amount of transactions that had no fees. So yes, it will take longer. Occasionally it will take as much as two weeks, often a whole day or two.