-4

Couldn't you use brute force to guess someone’s binary number because it's 1 or 0 - 256 times then just keep switching 1's and 0's around- which then can be converted hexadecimal to guess their bitcoin private key?

user214558
  • 1
  • 1
    I have absolutely no idea what you're asking. What does 1 and 0 have to do with brute force? – forest Aug 14 '19 at 03:42
  • 6
    *"... 1 or 0 - 256 times ..."* - the amount of possible combinations are 2^256 which you cannot try with all computers combined even in the time earth existed so far. – Steffen Ullrich Aug 14 '19 at 04:12
  • 2
    To add to what @SteffenUllrich already said, the short answer is: No. You cannot just keep switching 1s and 0s around to guess their private key. – Xander Aug 14 '19 at 05:35
  • Possible duplicate of [Amount of simple operations that is safely out of reach for all humanity?](https://security.stackexchange.com/questions/6141/amount-of-simple-operations-that-is-safely-out-of-reach-for-all-humanity) – Benoit Esnard Aug 14 '19 at 06:29
  • If "switching 1's and 0's around" should make any sense, you must know how many 1's and how many 0's are there, and I don't see where that knowledge would come from (and with 128 - the best case - 1's there's still ~10^75 256 bit numbers, still quite a few guesses to make) – Henrik supports the community Aug 14 '19 at 15:39

1 Answers1

1

Yes, in theory, you could just brute-force every secret there is. In practice, it's not feasible.

A practical demonstration

I'm going to think of a random number between 0 and 10, and you will have to guess which one it is. Did you make your guess? Correct, it was 2! Even if you did not make your guess correctly, if I would stay with the same number and you could keep guessing, sooner or later you would have exhausted all options and found the number.

Now I will think of a random number between 0 and 115792089237316195423570985008687907853269984665640564039457584007913129639935, and again you have to guess. Did you make your guess?

I'm fairly confident that you guessed wrong. In fact, I could keep you guessing for a full year, and you wouldn't be able to find it. You could even rent a server farm in the Arctic, let that server farm make billions and billions of guesses per second, and I am still confident you wouldn't guess my number, just because of how absurdly large it is.

If you would like to know more about a physical demonstration that it's impossible, even if we were to invent faster and faster CPU's, look at this beautiful answer by Thomas Pornin.