Is this possible?

[sdmathis]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

[redsn0w]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

Hmmm it will be extremely difficult (to find an address with some deposited bitcoins) or maybe I don't understand your 'question'.

[sdmathis]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

Hmmm it will be extremely difficult (to find an address with some deposited bitcoins) or maybe I don't understand your 'question'.

What I mean is it theoretically possible, or is there something in the code that prevents it.

[Don007]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

Hmmm it will be extremely difficult (to find an address with some deposited bitcoins) or maybe I don't understand your 'question'.

I think you do understand the question.

I'm curious about this too. I think it actually is possible that you become an address which were coins sent to earlier (by accidence). I don't think you can only send coins to addresses that do already exist.

However, I think this is only theoretically possible in that case.

[Amph]

if you sent it to that address, then that address exist in the first place, it make no sense that someone receives those coins with a new address created in the future, because otherwise you wasn't able to send it

p.s. again with this, it wasn't for increasing my posts counts, simply i didn't understand what he was saying(i thought about collision at first)

[DannyHamilton]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

If you were lucky enough to generate the address that had the bitcoins, then yes you would find bitcoins just sitting in the wallet.

However:

Ok, new data, will recalc everything:

• probability of getting struck by lightning in any given year: 1/280000.
• probability of taking a shit at any given point in time: 1/(60*24) = 1/1440 (assuming you take a crap every day and the actual process takes 1 minute)
• probability of getting struck by lightning while taking a crap in any given year: 1/(280000*1440) = 1/1.47E11 = 2.48E-9
• probability of taking a crap while being in a situation where being struck by lightning can actually occur = 1/1440 = 0.25 = 1.74E-4
• probability of finding a collision: 1E-65
• getting hit by lightning while taking a crap for how many years in a row is equally probable as finding a collision: log(1E-65) / log(1.74E-4) = 17.3

is my math roughly correct now?

If so, I can say: "Finding a collision is about as likely as being struck by lightning while taking a crap every year for 17 years in a row".

For any reasonable understanding of the word "possible", it is not possible to find bitcoins in a truly random newly created address.

Now, if you can figure out some non-random system that someone else used to create a bitcoin address, then you could generate the same address and gain access to their bitcoins.  Of course, that would be theft, and you're not a thief, are you?

What I mean is it theoretically possible, or is there something in the code that prevents it.

No, the only thing that prevents it is the EXTREME odds against it happening.

- snip -
(a bunch of silly nonsense)
- snip -

- snip -
(a bunch of silly nonsense)
- snip -

You would do well not to take advice from anybody that has an advertisement in their signature space on this forum.

The vast majority of those are people that are being paid per post to advertise with those signatures.  Therefore, they'll say just about anything in a discussion thread just to increase their post count (and therefore increase their income).  Generally, they know less about the topic they are discussing than the person asking the questions.

[sdmathis]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

If you were lucky enough to generate the address that had the bitcoins, then yes you would find bitcoins just sitting in the wallet.

However:

Ok, new data, will recalc everything:

• probability of getting struck by lightning in any given year: 1/280000.
• probability of taking a shit at any given point in time: 1/(60*24) = 1/1440 (assuming you take a crap every day and the actual process takes 1 minute)
• probability of getting struck by lightning while taking a crap in any given year: 1/(280000*1440) = 1/1.47E11 = 2.48E-9
• probability of taking a crap while being in a situation where being struck by lightning can actually occur = 1/1440 = 0.25 = 1.74E-4
• probability of finding a collision: 1E-65
• getting hit by lightning while taking a crap for how many years in a row is equally probable as finding a collision: log(1E-65) / log(1.74E-4) = 17.3

is my math roughly correct now?

If so, I can say: "Finding a collision is about as likely as being struck by lightning while taking a crap every year for 17 years in a row".

For any reasonable understanding of the word "possible", it is not possible to find bitcoins in a truly random newly created address.

Now, if you can figure out some non-random system that someone else used to create a bitcoin address, then you could generate the same address and gain access to their bitcoins.  Of course, that would be theft, and you're not a thief, are you?

What I mean is it theoretically possible, or is there something in the code that prevents it.

No, the only thing that prevents it is the EXTREME odds against it happening.

I never thought of that. Generating the same address as someone else. Is that theoretically possible? Or is there a mechanism in place to ensure that never happens?

I know that the odds make it almost impossible.

[kolloh]

I never thought of that. Generating the same address as someone else. Is that theoretically possible? Or is there a mechanism in place to ensure that never happens?

I know that the odds make it almost impossible.

Yes, there is nothing in place to ensure the same address is not generated. However, the odds make it nearly impossible so you really don't have to worry about it.

[DannyHamilton]

I never thought of that. Generating the same address as someone else. Is that theoretically possible?

That depends on what you mean by "theoretically possible".

If the address is generated in a truly random way (as it should be), then it isn't possible by any reasonable sense of the word.

For example, all the air molecules are randomly moving around the room you are in.  As such, any configuration of those molecules is "theoretically" possible.  Perhaps the molecules will all randomly end up bunched up in one corner of the room, and you will suffocate. It's never going to happen, but would you consider that to be "theoretically possible"?  Most reasonable people would not consider it possible at all and wouldn't spend any thought power on worrying about it.

Or is there a mechanism in place to ensure that never happens?

The only "mechanism" is the EXTREME odds against it as long as the addresses are generated randomly.  If you use some non-random system to generate an address, then it becomes possible that someone else could figure out the same non-random system and generate the same address.

I know that the odds make it almost impossible.

Not "almost" impossible.  The odds make it impossible. (by any reasonable use of the word as long as the addresses are generated in a truly random way.)

Oh, and I see that you have a signature ad. I won't see anything else that you post, and therefore won't be sharing any additional knowledge with you.

Plonk!

[sdmathis]

I never thought of that. Generating the same address as someone else. Is that theoretically possible?

That depends on what you mean by "theoretically possible".

If the address is generate in a truly random way (as it should be), then it isn't possible by any reasonable sense of the word.

For example, all the air molecules are randomly moving around the room you are in.  As such, any configuration of those molecules is "theoretically" possible.  Perhaps the molecules will all randomly end up bunched up in one corner of the room, and you will suffocate. It's never going to happen, but would you consider that to be "theoretically possible"?  Most reasonable people would not consider it possible at all and wouldn't spend any thought power on worrying about it.

Or is there a mechanism in place to ensure that never happens?

The only "mechanism" is the EXTREME odds against it as long as the addresses are generated randomly.  If you use some non-random system to generate an address, then it becomes possible that someone else could figure out the same non-random system and generate the same address.

I know that the odds make it almost impossible.

Not "almost" impossible.  The odds make it impossible. (by any reasonable use of the word as long as the addresses are generated in a truly random way).

That's exactly what I was wondering. Thanks.

[JackRipper]

I've wondered about that too. Thanks @DannyHamilton for your explaination.

[Astargath]

I never thought of that. Generating the same address as someone else. Is that theoretically possible? Or is there a mechanism in place to ensure that never happens?

I know that the odds make it almost impossible.

Yes, there is nothing in place to ensure the same address is not generated. However, the odds make it nearly impossible so you really don't have to worry about it.

What do you mean by the same address? Like you can have an address and someone may get the same address?? Or am i not understanding this correctly?

[CoinFriend]

Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?

A while ago i asked my self the same question...

And yes, i agree with DannyHamilton's answers.
It is possible, but the chance that two people generate the same address and that someone has deposit coins on it is very very very small! It seems nearly not impossible...

And please think about the fact that you are able to also generate a address on a computer without internet connection. And you can send coins to this address without that this computer was connected to the internet ever.
This way i learned that a address is not bound to a user or to a wallet. And it means that there is not a mechanism which prevents that a address can generated more as to times.
The procedure of generating a address offline is good for some reasons, ( and the safest ) for example to generate a address and a private key to print it on a paper. Or for generating a unique address ( a vanity address). No hacker or bad software is able to find a offline generated address. And i am not able to calculate how long it could need to bruteforce a private key of a address with coins deposited on it. I think it is not possible during my lifetime, even if with computer which are 1000 times faster than today.

[virtualx]

Once when I first started getting into crypto, I accidentally sent sone altcoins to the wrong address and of course, that was that. The coins were gone.

That made me wonder if the following scenario is possible: Could someone create a brand new Bitcoin address and find Bitcoin sitting in his wallet if someone accidentally sent coins to that address a year or so ago?  Or will coins only show up if someone sends them to the wrong address and that address already exists.

I was just curious.

It is impossible because of the length of the private key.  A bitcoin private key is usually a 256 bit number, where a bit is a choice between 0 or 1.  You must throw a coin 256 times and get each of the heads and tails combinations exactly right. 256 throws, you can do that right?

There are 2^256 possibilities. Guess the number below 115.792.089.237.316.195.423.570.985.008.687.907.853.269.984.665.640.564.039.457 .584.007.913.129.639.936.
If you can do that, you have the control. The chance of this randomly occurring? 1/ (2^256). Practically zero.

Newer wallets may use BIP 32 seeds for their private keys, which can be as long as 512 bits. There is also the risk of have a multi signature address where you need to guess not only one private key but four or more.

[Icardi09]

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

[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?

[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. 

[Astargath]

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. 

I heard some scientists saying that it still may be impossible in the futute because computers will have a limit on how fast they can process information, since information itself cant travel faster than light

[Light]

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.  

I heard some scientists saying that it still may be impossible in the futute because computers will have a limit on how fast they can process information, since information itself cant travel faster than light

Holy crap, the amount of misinformation in this thread is mind boggling.

First off, the theoretical limitation IIRC is because of thermodynamics NOT the speed of light. Everything you do (including calculations) requires energy. There is a minimum amount of energy required for any single calculation and hence you require incredible amounts of energy to actually bruteforce the entire keyspace.



This isn't entirely true as the security of Bitcoin depends on SHA-256, RIPEMD-160 and ECDSA being secure - but bruteforce attacks are not viable.

[notlist3d]

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.  

....saving space
Holy crap, the amount of misinformation in this thread is mind boggling.

First off, the theoretical limitation IIRC is because of thermodynamics NOT the speed of light. Everything you do (including calculations) requires energy. There is a minimum amount of energy required for any single calculation and hence you require incredible amounts of energy to actually bruteforce the entire keyspace.
... saving space

So I am right it would be after we are dead.  If you look into bruteforcing there are breakthroughs at times such as when the industry went from CPU to GPU to crack many things, this was a huge advancement.  And there is always Moores Law.

I did not do the math as it is something that is not plausible.   Not trying to pass misinformation.