2^256 is a very large number. If you could build a computer that required a single atom, and could test the balance of a single account in a single nanosecond, and then converted the entirety of the earth into such computers, it would take ~2.8 million years for you to check 0.01% of all accounts.
Brute-forcing modern cryptography isn't something that can happen. The magnitude of 2^256 is close to the count of atoms in the entire observable universe.
"... brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space."
Look more carefully, the estimation according to Wikipedia is 10^80, which is roughly 2^266.
(BTW, when converting 10^x to 2^x, times 3 is what I use for very rough back of the envelope estimations. Times 10/3 is actually almost precise, as log2(10) = 3.32…)
This reminds me of a discussion a few years ago where someone was extremely adamant that you'd have to handle the chance of a key collision in a random 256-bit key for the system to be secure :)
2^256 is a very large number. If you could build a computer that required a single atom, and could test the balance of a single account in a single nanosecond, and then converted the entirety of the earth into such computers, it would take ~2.8 million years for you to check 0.01% of all accounts.
Brute-forcing modern cryptography isn't something that can happen. The magnitude of 2^256 is close to the count of atoms in the entire observable universe.