Is it possible to create same private key by luck ?

[berkekaya]

today this banging question came to my head...
   As you know, all wallets with no transactions that you've created are actually assuming as not created before until it makes a transaction, so what if 2 people on the earth accidentaly creates same bitcoin adress by luck (paper,cold,node wallets ex...)and one of them buys a bitcoin and transfers into that wallet, what would be ?
i know that maximum  2^160 or something total keys can be generated on bitcoin network so it has its limits, and when there is a limit there is a chace too. lets talk about this...

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[mk4]

It's technically possible to generate the same exact private keys. But if were talking about probability, then it's pretty much next to impossible. Really not anything that we should be concerned of.

[20kevin20]

This was a question that's always given me a headache until I got it right. The thing is, while it is possible (as in the chances are not zero), the chances you have are just so low and close to 0 you'd probably have more luck winning a lottery multiple times instead.

Even if you had the astronomically low chance of generating an already used privkey and somehow managed to be the one to do it, an used privkey does not necessarily mean it also has a balance on it.

If someone ever happens to be "lucky enough" to generate the same key as someone else who still has it as an active wallet, the best thing they can do is just leave the address alone once they find out and move their funds to another wallet. Otherwise, taking someone else's funds has a simple definition: theft.

Many things have a probability, but it doesn't mean they will also ever happen/exist. Generating two identical privkeys is one of them.

[o_e_l_e_o]

There are just less than 2²⁵⁶ possible private keys.
There are 2¹⁶⁰ possible addresses.
There are 30 million addresses with a balance.
You therefore have a 30 million in 2¹⁶⁰ chance of finding an address with a balance per address you generate.
This is approximately 1 in 5*10⁴⁰.

The US powerball has odds of matching all 5 numbers and the powerball of around 1 in 3*10⁸.

Therefore, you are roughly as likely to win the powerball jackpot 5 times in a row as you are to find an address collision.

[Dsdaq]

The only way this will ever happen is if you give someone your private key. It will never happen by random chance. Never. You'd have a better chance of winning the lottery twice, getting struck by lightning and being mauled by two gorillas all in the same day. Instead of worrying about generating a private key that someone already has, you'd be better off worrying about how to protect yourself from lightning and gorillas so you can spend the money you'll win in the lottery.
So as long as you keep your private key private, you will never have to worry about this.

[Expecto]

It is possible to create the same private key. But the chances are at a very low level that you shouldn't have any worries about it. Probably, you have more chance to win the lottery than creating the same private key with someone else. 

[TedMosby]

There’s a chance that it will be happened, but the chance neglected to impossible, or almost impossible.
CMIIW.

You can read the discussion of this topic on this thread.
https://bitcointalk.org/index.php?topic=5255317
It has been discussed 4 months ago on this forum.
You could lock this thread and start discuss it there.

[j2002ba2]

There are just less than 2²⁵⁶ possible private keys.
There are 2¹⁶⁰ possible public keys.

There are just less than 2²⁵⁶ possible public keys.
There are 2¹⁶⁰ possible P2PKH addresses.

[Blackrain13]

It is possible if you share your private key to other so that you both have the same wallet address and private key, right?
The truth is possible but it's you are shooting the moon and star. And why do you want to create same private key with others? Is it like you want to steal others funds...oh....that's not good. So, don't even think or try to create a private key same with others because for sure it will cause you a too much headache.

[BlackHatCoiner]

The forum experts stated really well what are the possibilities of generating the same address with someone else. You can try your luck on this thread, though.

I would like you to check that too. (Made by me :p)

Otherwise, taking someone else's funds has a simple definition: theft.

Many things have a probability, but it doesn't mean they will also ever happen/exist. Generating two identical privkeys is one of them.

It hasn't ever happened, and it won't, but even if someone stole the funds, what could the victim do? It isn't an actual theft. He didn't broke into his house or hacked his computer. I think that the "thief" can keep the funds legally.

[Pulsar77]

Even though it is theoretically possible, it is an impossible situation in practice. The probability of something like this happening is 0.000000000001%. The possibility of two different people having the same fingerprint is higher than this.

[hatshepsut93]

You are making a typical mistake of a newbie - worrying about the wrong things. "What if two people generate the same key", "what if someone bruteforces a privatekey", "what if quantum computers", "what if all bitcoins are mined" - these things aren't going to affect Bitcoin in the nearest future or even ever. What you should personally be focusing on is avoiding any malware in your system, avoiding phishing, verifying digital signatures on all software you install, maintaining your privacy to avoid physical robbery.

[o_e_l_e_o]

It isn't an actual theft. He didn't broke into his house or hacked his computer. I think that the "thief" can keep the funds legally.

Breaking and entering or illegal access is not a prerequisite to stealing. It is absolutely theft and is absolutely illegal.

What if I tried to log in to an online banking service with a random username and password, which happened to match the account of a real customer? Can I legally take all their money?
What if I tried to buy something online, entered some random details and a random credit card number, which happened to match the details of a real card holder? Can I max out their credit cards?
Why are these situations any different to someone randomly entering your private key?

[BlackHatCoiner]

Why are these situations any different to someone randomly entering your private key?

There is a difference with private key and those you mentioned. If I enter some random details on a bank and successfully have access to someone's money, it will be considered illegal to move them since the person owns them, not me. The money are written on his name.

On the bitcoin world, though, there is anonymity. If you give me your private key, how exactly are you going to prove that you were the first owner of the keys? (so it would be considered that I stole them from you)

[Ridcan]

mathematically what you say may seem possible.  it may seem technically possible.  However, it is very unlikely that you will encounter such a situation.  Since the probability of not happening is much higher than the probability of it, it would be correct to call it impossible. 

[o_e_l_e_o]

On the bitcoin world, though, there is anonymity. If you give me your private key, how exactly are you going to prove that you were the first owner of the keys? (so it would be considered that I stole them from you)

That doesn't mean the coins on the address are any less "mine", just because they are not attached to my real name. By that logic, Sstoshi doesn't own a single satoshi. What if I find a briefcase with a million dollars in cash on the street? I don't require to break in anywhere to take it, and there is no name attached. That doesn't mean I can legally keep it.

If you give me your private key, how exactly are you going to prove that you were the first owner of the keys? (so it would be considered that I stole them from you)

I could provide a zero knowledge proof that I am in possession of the extended private key or the seed phrase which was used to derive that private key.

[carlisle1]

today this banging question came to my head...
   As you know, all wallets with no transactions that you've created are actually assuming as not created before until it makes a transaction, so what if 2 people on the earth accidentaly creates same bitcoin adress by luck (paper,cold,node wallets ex...)and one of them buys a bitcoin and transfers into that wallet, what would be ?
i know that maximum  2^160 or something total keys can be generated on bitcoin network so it has its limits, and when there is a limit there is a chace too. lets talk about this...

With millions and millions of combinations?i believe that the possibility is really rare to happen mate though it is possible as what the experts says above.
so basically this will happen once in a million or billion chances .

mathematically what you say may seem possible.  it may seem technically possible.  However, it is very unlikely that you will encounter such a situation.  Since the probability of not happening is much higher than the probability of it, it would be correct to call it impossible. 

LOl yeah that is almost impossible to happen as what i mentioned above probability .

[jaresmerel001]

The private keys are 256 bits long. Solving its corresponds to an exponential complexity of 2 ^ 254 in computation. You'd have to guess a number with 256 digits in it. It would take longer than the universe's lifespan.

[j2002ba2]

Some random thoughts on coins and ownership.

Private keys give possibility to sign transactions. All ownership is on the other hand a fiction, fantasy. It does not exist in reality.

Owning something means everybody else agreeing or being forced to agree to it. This makes some sense locally, (and could be highly beneficial), but for a global thing like bitcoin it's total bullshit. Owning bitcoin then means owning a number. A number can be known or unknown. Owning a number then is forbidding everyone to know a certain number. How ridiculous.

Since bitcoin is decentralized, no one could own coins. Otherwise it is not decentralized. So you have to choose. To bend it to law, bring ownership and centralize it. Or to let it be decentralized, and instead of owning, have access. We could see the push to centralize it - "tainted coins", KYC/AMLx, trying to force you to own coins instead of having access.

Some people (all?) have access to some coins, and think they own it. It's a lot like the access to "your" body, or to "your" mind, or to anything "yours". The day comes, when access is gone. It's a matter of time.

Getting access to some random coins could be impossibly hard, maybe one of the hardest problems right now. Knowing the public key(s) makes it less hard, but still impossibly hard.

[dothebeats]

Technically possible, but the chances of this happening in millions of lifetimes is close to nil. I'll consider myself lucky and bet on lottery tickets if I were to ever be in the receiving end of a collision in private key generation, as that in itself is extremely rare--and the word 'extremely' isn't even enough to justify just how close to impossible it is.

The question has been pondered upon by many newbies and old-timers alike. This is a good yet kinda short discussion on the same topic: https://crypto.stackexchange.com/questions/33821/how-to-deal-with-collisions-in-bitcoin-addresses