The numbers for this, sadly (or gladly, for holders of bitcoin), don't work out. Even if you had the most powerful supercomputer in the world and could try trillions upon trillions of keys per second, you'd need, on average, more than the current age of the universe to brute-force the key.
In order to spend money sent to a Bitcoin address, you just need to find a ECDSA public key that hashes to the same 160 bit value. That will take, on average, 2 ^ 160 key generations.
Supposing you could generate a billion (2 ^ 30) per second, you need 2 ^ 130 seconds.
Doing this in parallel using a billion machines requires only 2 ^ 100 seconds.
Getting a billion of your richest friends to join you gets it down to only 2 ^ 70 seconds.
There are about 2 ^ 25 seconds per year, so you need 2 ^ 45 years.
The age of the Universe is about 2 ^ 34 years so far—better get cracking!
Comments
The numbers for this, sadly (or gladly, for holders of bitcoin), don't work out. Even if you had the most powerful supercomputer in the world and could try trillions upon trillions of keys per second, you'd need, on average, more than the current age of the universe to brute-force the key.
From: http://bitcoin.stackexchange.com/questions/22/is-it-possible...
In order to spend money sent to a Bitcoin address, you just need to find a ECDSA public key that hashes to the same 160 bit value. That will take, on average, 2 ^ 160 key generations.
Supposing you could generate a billion (2 ^ 30) per second, you need 2 ^ 130 seconds.
Doing this in parallel using a billion machines requires only 2 ^ 100 seconds.
Getting a billion of your richest friends to join you gets it down to only 2 ^ 70 seconds.
There are about 2 ^ 25 seconds per year, so you need 2 ^ 45 years.
The age of the Universe is about 2 ^ 34 years so far—better get cracking!