Here's some good reading about address collisions/exhaustion.
https://bitcointalk.org/index.php?topic=3462.0;allhttps://bitcointalk.org/index.php?topic=27277.0;allhttps://bitcointalk.org/index.php?topic=26278.0;allIf every person on Earth makes ten addresses per second for 20 years (2x1018 total addresses), then the probability that two of these addresses collide is about 1.57x10-12.
A committed individual or organization could easily aquire network storage in the Petabytes. I think that would be more than enough to get a sizable operation started.
1 petabyte is 10
15 bytes.
There are 2
160 possible BTC addresses, each of which is 160 bits == 20 bytes long.
So to store all of them you need 2
160x20 bytes, which is 29,230,032,746,618,058,364,073,696,654,325,660 petabytes.
Bear in mind, we are not looking for a single address among the clouds here. We are looking for -any- address containing BTC.
Suppose each of the 7 billion people in the world has 1000 unspent addresses. On average you would need to try more than 10
35 addresses to find each spendable one. Suppose you can check a million addresses per second, this is going to take you more than 10
21 years.
If everyone in the world is trying to crack this at the same time, it will still take around 10
12 years. And when someone finally cracks it, after paying the electricity bill for 10
12 years, they might be disappointed to find that the key unlocks just 0.05 BTC from the Bitcoin Faucet. Even if it's ten million bitcoins, it's not going to pay the electricity bill for 7 billion computers running for a trillion years.
In short, don't worry about it.
Sorry for digging up an old thread but how can we be certain that this many bitcoin addresses exist if we are not able to generate and store them? Are most bitcoin addresses just theoretical?