Post
Topic
Board Development & Technical Discussion
Re: Vanity bitcoin addresses: a new way to keep your CPU busy
by
joan
on 29/06/2011, 21:17:04 UTC
If mining hardware was instead dedicated to generating new addresses; how long do you think would it take till someone stumbled on an existing address that had more BTC stored than what the person would have earned by mining?

(…)

Their are 2^160 possible addresses. Lets say 2^32 (4 billion) people use Bitcoin and each generate 2^16 (65 thousand) address. That gives us 2^48 total addresses out of 2^160 possible. The probability of a generated address matching one of these is 1/(2^112).

The probability for two addresses to match is much higher than 1/(2^112) though. It's more complex than doing 2^160/2^48. Check the Birthday attack.
Also, TiagoTiago mentionned using current mining resources to generate addresses, so I guess it's fair to say that the 2^16 figure is underestimated, that would be more like… 2^16 per second. (But there is not 4 billion miners, yet)

While we are on probabilities, and I'm by no means an expert in these, someone mentioned in a previous page of this thread that to find the "1Kahlahan…" vanity address (8 fixed chars) would take roughly 1.28e14 attempts.
I think this is underestimated. (It seems to come from the intuitive 58^8).
My own computation gives me 2.99e+15, which is an order of magnitude higher. (I decode the base58 and do the maths on the hash160).