Security of Bitcoin Address

[krashfire]

What are the chances of anyone accidentally creating the same Bitcoin address? Is it remotely possible or there is some kind of checks before network, software, God or something would do a check first before approving the Bitcoin address. Again, I'm just thinking out loud. Hmmm...🤔

[1715683851]

1715683851

[1715683851]

1715683851

[hosseinimr93]

What are the chances of anyone accidentally creating the same Bitcoin address?

In theory, that's possible. In practice, that's impossible.
Take note that there are 2¹⁶⁰ valid bitcoin addresses (There are even more addresses if consider all types of bitcoin addresses).

Is it remotely possible or there is some kind of checks before network, software, God or something would do a check first before approving the Bitcoin address.

No.
Note that your bitcoin address in generated through some mathematical calculations from a random number and you don't need internet connection for that.

[Plaguedeath]

There's an answer in old thread, my suggestion if you have a question, it's better to use google search by type "bitcointalk.org: your question", but if you don't find any answer then you can create new thread.

AFAIK I haven't see anyone create a thread when they create a new wallet, the wallet have been funded (which mean someone have been use this existing wallet).

This would be called a "collision" and is highly unlikely.

Keys are 256 bit in length and are hashed in a 160 bit address.(2^160th power) Divide it by the world population and you have about 215,000,000,000,000,000,000,000,000,000,000,000,000 addresses per capita.(2.15 x 10^38)

[rat03gopoh]

Here is a good parable.

Given your example of 1 billion users at 10 addresses each:

There are 2^160 or about 1,460,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible addresses
In your scenario, 1,000,000,000 people are using 10 addresses each for a total of 10,000,000,000 possible addresses
10,000,000,000 / 2^160 should yield the probability of a collision occurring
10,000,000,000 / 2^160 = 0.00000000000000000000000000000000000000684

So the chances of a collision occurring in your scenario are approximately 0.000000000000000000000000000000000000684%

Possibility increases drastically when there is divine intervention.

[hosseinimr93]

AFAIK I haven't see anyone create a thread when they create a new wallet, the wallet have been funded (which mean someone have been use this existing wallet).

That can happen only if you use a malicious tool. There have been cases that people got a used pre-generated address from a malicious paper wallet generator.
If your private key is generated randomly, it's impossible that you generate an address that has been generated by someone else before (Of course, in theory that's possible).

[Clark Anderson]

It is literally not possible for two different users to create the same Bitcoin address. For every wallet, a unique private key is created and this key only links to one wallet so the odds of this happening is very low. Or maybe I just haven't seen any case where this senerio actually occurred and even though there is, it would be rare.

[Charles-Tim]

Not possible, but if you are having doubt and want to feel more secure about your seed phrase, use passphrase.

AFAIK I haven't see anyone create a thread when they create a new wallet, the wallet have been funded (which mean someone have been use this existing wallet).

That can happen only if you use a malicious tool. There have been cases that people got a used pre-generated address from a malicious paper wallet generator.

Also there were or even maybe still some fake wallets on playstore that are just fake. If used to generate a wallet, it will only result to the fake developers to steal the coin. Some of the wallets contains pre-generated seed phrase and addresses.

[Aanuoluwatofunmi]

What are the chances of anyone accidentally creating the same Bitcoin address?

It's more likely impossible because there's a designed pattern to how the wallet addresses are being generated even without the internet connectivity, there are some computation that work underground that determines the generation of bitcoin wallet address and this procedures are no repeated twice on randomization of both numbers and figure base on the computation capacity of the wallet type and how it was being programmed.

[LoyceV]

Start by guessing my phone number. Then give me a call, and guess my credit card number. Chances of getting both right are still about a sextillion times more likely than guessing my private key. In short: don't worry about it, but feel free to try for yourself: here's a list of all funded Bitcoin addresses.

[krashfire]

Here is a good parable.

Given your example of 1 billion users at 10 addresses each:

There are 2^160 or about 1,460,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible addresses
In your scenario, 1,000,000,000 people are using 10 addresses each for a total of 10,000,000,000 possible addresses
10,000,000,000 / 2^160 should yield the probability of a collision occurring
10,000,000,000 / 2^160 = 0.00000000000000000000000000000000000000684

So the chances of a collision occurring in your scenario are approximately 0.000000000000000000000000000000000000684%

Possibility increases drastically when there is divine intervention.

lol

I like your answer.

There's an answer in old thread, my suggestion if you have a question, it's better to use google search by type "bitcointalk.org: your question", but if you don't find any answer then you can create new thread.

AFAIK I haven't see anyone create a thread when they create a new wallet, the wallet have been funded (which mean someone have been use this existing wallet).

This would be called a "collision" and is highly unlikely.

Keys are 256 bit in length and are hashed in a 160 bit address.(2^160th power) Divide it by the world population and you have about 215,000,000,000,000,000,000,000,000,000,000,000,000 addresses per capita.(2.15 x 10^38)

alright. Noted.

[moderator's note: consecutive posts merged]

[CryptSafe]

What are the chances of anyone accidentally creating the same Bitcoin address? Is it remotely possible or there is some kind of checks before network, software, God or something would do a check first before approving the Bitcoin address. Again, I'm just thinking out loud. Hmmm...🤔

This question is just like you asking your parents to give birth to somebody just exactly like you in resemblance, character, attitude and every aspect of you and do you think you will be of the same age too?
This question you have asked is rhetorical. If that should happen then what is the possibility that your funds would be safe because the probability of having same wallet keys is narrow if it is feasible. So OP,  I do not think you will really get a clearer picture of what you want neither will you get a direct answer for this question you have just asked. Just as LoyceV has said, you can start that way and wait for your answer.

[Justtoons]

Let's look at this from the aspect of a normal bank account, after you create a bank account, you are given a unique account number, that only links to your bank account. And until your account becomes dominant this number remains yours and yours only.


That same way, wallet addresses are created from secured hash algorithms, which produces a private key just like your bank pin for transactions. And also you are given unique address (just like your bank account no) for a wallet and can only be used for one wallet.

What are the chances of anyone accidentally creating the same Bitcoin address? Is it remotely possible or there is some kind of checks before network, software, God or something would do a check first before approving the Bitcoin address. Again, I'm just thinking out loud. Hmmm...🤔

I really don't think it's possible for two persons to have the same wallet or Bitcoin address.

[hosseinimr93]

Let's look at this from the aspect of a normal bank account, after you create a bank account, you are given a unique account number, that only links to your bank account. And until your account becomes dominant this number remains yours and yours only.

You are right about how a bank account number works, but take note that there's a big difference between a bank account number and a bitcoin address.

Even in theory, it's impossible that there are two different persons with the same bank account number. The bank account number is given to you by a centralized service while your bitcoin address is generated by yourself and in theory it's possible that two persons generate the same bitcoin address.

[LoyceV]

which produces a private key just like your bank pin for transactions.

That's a terrible comparison. Tens of thousands of people all have the same PIN number for their bank cards. Private keys are unique.

And also you are given unique address (just like your bank account no) for a wallet and can only be used for one wallet.

That's not true either. If you want, you can use the same Bitcoin address from different wallets.

you as a user can not create a Bitcoin address without going through verification and confirmation of the validity of the address before authentication, so don't be so gullible not to notice the error message of the address if not valid or valid to an already existing wallet.

You're posting in the wrong topic, this belongs in Wall of fame / shame. Shit posts so bad that they are actually funny.

[hosseinimr93]

It's not possible because you as a user can not create a Bitcoin address without going through verification and confirmation of the validity of the address before authentication, so don't be so gullible not to notice the error message of the address if not valid or valid to an already existing wallet.

When your wallet generates an address from a private key, it doesn't check whether the address has been used before or not and there is no way to know whether the address has been generated by someone else before or not.
As already said above, due to having a very large number of bitcoin addresses, it's not possible that the address you generate randomly has been already generated before. It's not that there's a database of addresses which is used by your wallet to check whether the address has been generated before or not.

[Dr.Bitcoin_Strange]

In theory, that's possible. In practice, that's impossible.
Take note that there are 2¹⁶⁰ valid bitcoin addresses (There are even more addresses if consider all types of bitcoin addresses).

In my place, when someone registers a SIM-Card and after using it for some times (months or years) they get rid of it either by mistake or intentionally, the network provider gives a duration of about 8 months or a year, if the SIM-Card is in-active for the duration of 8 months, it became recycled and sold to another customer.

My question here is, the way Bitcoin wallets are programed and being generated, is it also certain that old unused Bitcoin addresses (that was generated by someone but was not used or probably lost his phrase) can never be recycled by the system to be used again?

[BlackHatCoiner]

My question here is, the way Bitcoin wallets are programed and being generated, is it also certain that old unused Bitcoin addresses (that was generated by someone but was not used or probably lost his phrase) can never be recycled by the system to be used again?

Nobody can act as your SIM provider in a decentralized network. Bitcoin addresses don't expire. They don't get recycled either. Just because someone lost his private key, it doesn't let the network magically gains access to it. There are about 2^96 other keys that can create a valid signature for that specific address either way.

Furthermore, there is no need for recycling. The number of private keys is stupidly big.

[hosseinimr93]

My question here is, the way Bitcoin wallets are programed and being generated, is it also certain that old unused Bitcoin addresses (that was generated by someone but was not used or probably lost his phrase) can never be recycled by the system to be used again?

It's not that there's a database of addresses and there's a bitcoin address provider that gives an address to every user.
You can generate numerous bitcoin addresses through some mathematical calculations even without any internet connection. So, your address isn't registered anywhere and as long as the address hasn't been funded, no one can know such address has been generated.

Take note that your sim-card provider is a centralized service that has full control over everything related to your sim-card. In bitcoin, there is no third party at all. No one has control over addresses and transactions.

[Nwada001]

In my place, when someone registers a SIM-Card and after using it for some times (months or years) they get rid of it either by mistake or intentionally, the network provider gives a duration of about 8 months or a year, if the SIM-Card is in-active for the duration of 8 months, it became recycled and sold to another customer.

My question here is, the way Bitcoin wallets are programed and being generated, is it also certain that old unused Bitcoin addresses (that was generated by someone but was not used or probably lost his phrase) can never be recycled by the system to be used again?

To my own understanding, Bitcoin addresses are generated through the private key/phrase of each wallet, and the same way two wallets can't have the same private key, an old wallet address can't be replaced no matter the duration of being inactive. 
 
In the cases where a Sim is given to another user after months or years of inactivity, it's because of the need to manage storage space. The more new numbers generated, the more storage space is needed, so to manage storage space, they have to minimize the amount of new numbers being produced. That's why the policy of selling out old mobile numbers to new customers is being implemented. But the case of Bitcoin is different.

[Flexystar]

What are the chances of anyone accidentally creating the same Bitcoin address?

In theory, that's possible. In practice, that's impossible.
Take note that there are 2¹⁶⁰ valid bitcoin addresses (There are even more addresses if consider all types of bitcoin addresses).

Is it remotely possible or there is some kind of checks before network, software, God or something would do a check first before approving the Bitcoin address.

No.
Note that your bitcoin address in generated through some mathematical calculations from a random number and you don't need internet connection for that.

Well very good question raised by OP (curious one) and nicely explained here as to what can happen. Good to know that we will tiny to no possibility of having same address getting generated.

There are hundreds of examples that explain how it is not possible or highly unlikely to get messed up in this situation. I think if it happens it would start the chain reaction of chaos on a blockchain. Imagine spending bitcoins twice because it was initiated from the same sender address. Not sure whether two owners will get benefited if someone credits to that address (off course in parallel universe if the addresses are same!)

But then, again I got impressed with the following example from one of the article associated with likelihood of hitting same person when you walk around FRANCE. Very nicely explained, everyone must read this to understand its not possible that we will have same address again.

What does it match to?
Let’s try to evaluate the size of such a figure through an analogy. Imagine that you have a computer capable of generating 400,000 Bitcoin addresses per second, which already requires significant computing power.

Start the computer, and go for a walk. For example, complete the Tour of France (6397 km), walking at a normal pace of 4 km/h. Once you have finished your walk, say hello to a random person, and start your walk again. Once you have said hello to 66 million inhabitants, and completed the Tour de France each time, visit one of the 36,000 French municipalities.

Now repeat your tours of France, your greetings to each inhabitant, and when you have finished visiting all of the French municipalities, you will probably have generated a Bitcoin address collision with your computer.

The computer in question would then need 10 million billion of hard drives to store such a large amount of data. Unfortunately, here is the bad news: there is no guarantee that the address on which you generated a collision contains bitcoins: at present, only 10 million addresses have been used on the network.

The probability of generating a collision on an address containing bitcoins is therefore much lower, and it is highly likely that the Earth would have disappeared well before you finish your tours of France.

Conclusion: Don’t worry
All this is simply to say that one should not worry about the possibility that an address collision is generated by two different wallets. The creator of the Bitcoin network has devised a particularly well-adapted system, which, through decentralization, ensures that everyone has the opportunity to use the network without having to register the addresses of their wallets with anyone, and this without fear that two people will ever use the same address.

Full read here. The article also explains numerical calculations behind the possibility of this event happening. How there is 99.999% of chance it wont happen at all. Just a quick 2 minutes read.

What if my wallet generated an existing Bitcoin address?