Bitcoin Forum

So, I have a question.
I got a paper bitcoin wallet. On the frond side there is my public bitcoin address. On the back of the paper there is a private key.
On my smartphone i have a bitcoin app, which allows me to scan a private key and import bitcoins from the scanned address. Now, I would like to know if it is possible to brute force this private key if you know the Public key? I mean, It's pretty long, but I could imagine that if someone has some damn good CPU/GPU/RAM and a lot of time (6 months - 24 months), he would spend his time cracking Private keys off full wallets. Is it possible to crack a bitcoin address this way? How long would it take? Or am i completly wrong here? I am just thinking about this, because a friend of me has 4 BTC in a wallet, and i just think it is not safe to keep such a budget in an wallet covered by a basic charset key. (a-z;A-Z;0-9).
I just want to know.
Thx in advance,
xbmbmx.

It is possible to bruteforce the private key of an address, maybe in the next 500 years.

If you are worrying that someone would do it in your lifetime, no it is not possible. You can try it by yourself.

Just google "vanitygen".
Official thread is here: https://bitcointalk.org/index.php?topic=25804.0

You'll understand what a crazy idea it is once you try to brute force an address.  8)

If someone wants to brute force specifically your bitcoin wallet address, it will take unlimited time with the tech that is available nowadays. For example to get the private key of any address with the same first 9 charachters (case sensitive) is still impossible right now. So for exactly your bitcoin wallet address to be brute forced is simply impossible as of now.

Here's a good explanation, if you don't mind reading a long post. It will answer all your questions about bruteforcing a privet key by knowing a public one.
https://bitcointalk.org/index.php?topic=961023.msg10511733#msg10511733

In short, it's impossible. Do you think that if it was somebody wouldn't try to do it to one of Satoshi's addresses? It would be worth it even if you had to spend a year or 2 decrypting a single key.

I think you must read this, and make up your own mind --> https://www.weusecoins.com/amazing-math-bitcoin-private-keys/ .... The videos

are unfortunately private now, but it still gives you a pretty good idea how impossible it is.  ;) .... The risk involved with paper wallets are the

storage methods { how they are physically stored away } It should be a safe, dry place and you have to store duplicates in separate locations

for redundancy.  ;)

The simpler answer is given by itod:

When we can't fully comprehend something ourselves, we might try and find meaning that isn't there.  That applies to hacking Bitcoin wallets.  If you're really paranoid and need full security, just keep the Bitcoin that you're not spending offline or use a TREZOR (https://trezor.io/).

I understand. Its like trying to fill the universe with sand - There simply is not enough sand.
Thank you all for the responses!

_{If u would have too much bitcoins, you can always give this noob some money: 1B7Q9rHGSXJpbwugLdE3o8eNAZVkCL7hpr}
BTC Thanks again!

It is not possible. Check this video to understand the amazing math of bitcoin:

https://www.youtube.com/watch?v=ZloHVKk7DHk

It's theoretically possible in your lifetime.
In practice, you won't hack private key in lifetime. It will be only a waste of time, so you can share public address safely and no one will worry about your security.

Brother ! The key length used in Wallets is either 128 bits, 256 bits or 512 bits. it needs the attacker to try 2 power 128 or 2power 256 or 2power 512 combinations. It will take more than 80 years with all the computational powers in the world. So practically, it is not possible.

Yes, it is possible, however, we just have to import such advanced technology from the aliens as we don't have it yet and the situation is more likely to be the same until next few hundred years.

If you don't have any issues with such attack attempts after few hundred years then you can go for it, you are safe till then.

Thank all, I now have a better insight on Bruteforcing and key.Hope we are all safe with our wallets.