Is this possible?

[Amph]

you can't be really sure that is impossible, it maybe impossible for now, but there are numerous things that are still undiscovered, or not known well, like the dark matter

[CoinFriend]

I don't think someone can generate new address that actually used by another user before.
The chance getting this is very very small 
The length of private key is make sure there are so many bitcoin address out there

ha ha ha, why you use this smiley? -> 
it seems you have the wish, to generate (brute force) a address of your choice somehow ^^ right?

We just don't have the technology to do so.   The amount of time and power required to brute force this is hard to say.   It would take who knows how many years it could be after most of us are dead.

Maybe if a future far far away... but not going to happen anytime soon. 

haha, i wrote this already few posts before

.....
 I think it is not possible during my lifetime, even if with computer which are 1000 times faster than today.

but my question now is, HOW TO CALCULATE THE REQUIRED TIME 
lets assume i'm able to calculate private keys with ~33.33 Mkey/s

[notlist3d]

I don't think someone can generate new address that actually used by another user before.
The chance getting this is very very small 
The length of private key is make sure there are so many bitcoin address out there

ha ha ha, why you use this smiley? -> 
it seems you have the wish, to generate (brute force) a address of your choice somehow ^^ right?

We just don't have the technology to do so.   The amount of time and power required to brute force this is hard to say.   It would take who knows how many years it could be after most of us are dead.

Maybe if a future far far away... but not going to happen anytime soon. 

haha, i wrote this already few posts before

.....
 I think it is not possible during my lifetime, even if with computer which are 1000 times faster than today.

but my question now is, HOW TO CALCULATE THE REQUIRED TIME 
lets assume i'm able to calculate private keys with ~33.33 Mkey/s

I found this showing the math behind it - http://www.reddit.com/r/theydidthemath/comments/1x50xl/time_and_energy_required_to_bruteforce_a_aes256/

With a billion GPU's "The universe itself only existed for 14 billion (1.4e10) years. It would take ~6.7e40 times longer than the age of the universe to exhaust half of the keyspace of a AES-256 key."   So guess a new universe could be created before this happens.

[onurakkas]

unfortunetly it is impossible.

[JackRipper]

unfortunetly it is impossible.

It's not impossible, but it is highly improbable.

[CoinFriend]

I found this showing the math behind it - http://www.reddit.com/r/theydidthemath/comments/1x50xl/time_and_energy_required_to_bruteforce_a_aes256/

With a billion GPU's "The universe itself only existed for 14 billion (1.4e10) years. It would take ~6.7e40 times longer than the age of the universe to exhaust half of the keyspace of a AES-256 key."   So guess a new universe could be created before this happens.

thanks for your research, it's a good link and answers my questions

unfortunetly it is impossible.

It's not impossible, but it is highly improbable.

It's the way people look at this....
Someone who looks realistically to this topic says it is impossible.
Someone who say it is possible looks in a theoretical way, like a scientist for example.

I would say both answers are possible and acceptable as long someone can explain why he give this answer.

[odolvlobo]

At the risk of furthering this absurd conversation, I want to point out that if someone states that there is a probability of 1 in 2²⁵⁶ of guessing a private key, they are explicitly stating that it is possible to guess the key. If it were impossible, then the probability would be 0.

Now for those of you that don't yet grasp improbability of 1 in 2²⁵⁶, I give you this: https://www.youtube.com/watch?v=nFTRwD85AQ4

[Vod]

Now for those of you that don't yet grasp improbability of 1 in 2²⁵⁶, I give you this: https://www.youtube.com/watch?v=nFTRwD85AQ4

Love that movie!!!  Another interesting link:

http://rationalwiki.org/wiki/Improbable_things_happen

[sdmathis]

At the risk of furthering this absurd conversation, I want to point out that if someone states that there is a probability of 1 in 2²⁵⁶ of guessing a private key, they are explicitly stating that it is possible to guess the key. If it were impossible, then the probability would be 0.

Now for those of you that don't yet grasp improbability of 1 in 2²⁵⁶, I give you this: https://www.youtube.com/watch?v=nFTRwD85AQ4

I don't think that anybody is having trouble of grasping the improbability. My original question was "Is it possible?" not "Is it probable?" That question was answered, and I thank you for all the responses.

[Chemistry1988]

At the risk of furthering this absurd conversation, I want to point out that if someone states that there is a probability of 1 in 2²⁵⁶ of guessing a private key, they are explicitly stating that it is possible to guess the key. If it were impossible, then the probability would be 0.

Now for those of you that don't yet grasp improbability of 1 in 2²⁵⁶, I give you this: https://www.youtube.com/watch?v=nFTRwD85AQ4

CMIIW, you don't need to get the same private key but just a private key corresponding to the same address. If so, the chance would be 1 in 2^160 instead, am I right?

Anyway, it doesn't change the conclusion that a collision is not gonna happen, ever.

[shorena]

At the risk of furthering this absurd conversation, I want to point out that if someone states that there is a probability of 1 in 2²⁵⁶ of guessing a private key, they are explicitly stating that it is possible to guess the key. If it were impossible, then the probability would be 0.

Now for those of you that don't yet grasp improbability of 1 in 2²⁵⁶, I give you this: https://www.youtube.com/watch?v=nFTRwD85AQ4

CMIIW, you don't need to get the same private key but just a private key corresponding to the same address. If so, the chance would be 1 in 2^160 instead, am I right?

Correct. Well, it assumes further that the hashing algorithms (SHA256 and RIPEMD 160) used are evenly distributed, which is not proven AFAIK. Should the hashing algorithms be unevenly distributed could be some addresses with more corresponding private keys and some with less.

[Gultahin]

Wow what and awsome question, i was really going to crawl for an answer for that one, glad some on already found and shared with us, well at least it's not even "impossible" on a math carather.