If Bitcoin addresses can be generated offline, then the Bitcoin network doesn't check for duplicate addresses while generating a new one. Can't I just make a script and generate milions of Bitcoin addresses and then make a profit when someone will have one of those addresses and sends bitcoins there?
How does the Bitcoin network prevent this?
While this is theoretically possible, it is practically impossible.
Keys are 256 bit in length and are hashed in a 160 bit address.(2^160th power) Divide it by the world population and you have about 215,000,000,000,000,000,000,000,000,000,000,000,000 addresses per capita.(2.15 x 10^38
Probability prevents this from happening as the bitcoin address space is 2^160 or
1,461,501,600,000,000,000,000,000,000,000,000,000,000,000,000,000 (apx)
here is a picture to put it into perspective. Ok so now you are thinking well it is quick to generate them so I will just make more. Looking at this thread How to pre-generate 100M bitcoin addresses? you can generate 770k addresses in 15 minutes so lets do the math. that is
54,168,210,000,000,000,000,000,000,000,000,000,000 (apx)
years to generate all the bitcoin addresses. get cracking.
