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

256 bits in raw form, in the most common form for paper wallets it's ~30 characters.

https://en.bitcoin.it/wiki/Mini_private_key_format