Post
Topic
Board Bitcoin Discussion
Re: Bitcoin topic on Quora.com
by
riggasconi
on 23/01/2011, 18:30:02 UTC
Hi theymos,

thanks for the very technical answer.

No. Rewriting old blocks requires you to generate them again. So if you want to go back 6 blocks, you have to do the work required to generate them with the current difficulty and continue to compete against legitimate generators.

Why should an attacker want to go back, instead of just being faster than the honest network in producing a longer chain ?

Quote
That's much more difficult. A future version of Bitcoin will probably let the second recipient identify this attack immediately, since it is easy to see. A more likely attack is one where the second spend is back to the attacker.

1) Why do you say that a "backspend" is a better double-spending than a second spend towards a second recipient ?
2) How could a future Bitcoin client ever be protected from the double-spending exploit that currently affects Bitcoin ?