Topic: same private key? - page 3. (Read 1717 times)

Seed phrases are generally 12 or 24 words long, sometimes 15, 18, or 21, but pretty much never 36.

Given that each seed phrase can derive trillions upon trillions of addresses, then the same address will show up under two different seed phrases at different derivation paths. It is also possible that two different seed phrases (potentially with different specific passphrases), would generate the same 512 bit seed number and therefore identical wallets, but the chances of a collision in a 512 bit space is astronomically smaller than the already astronomically small chance of a collision in a 256 bit space.

So yes, it can theoretically happen, but no, it will never actually happen.

It's not possible for anyone to get your private because it is some sort of random generated alphabets which only you have authorized access to unless you gave it out or your wallet got compromised through hack and security breach or by submitting your private keys to fake and phishing sites.

The difference is that you can't guess 1 billion different credit cards in a second. There are blockers. They won't let you. In the private key, on the other hand, do your best!

Of course, I don't say, guessing the privkey is much harder that all of the things you've said, but you don't have the same opportunities.

I have a similar question to OP: can (not asking if likely or not, just asking if possible) collision occure in BIP39 Mnemonic?

For example, can a 12-word mnemonic produce the same wallet/pk/etc than, lets say, a 36-word mnemonic phrase?

Big numbers don't make people understand. Sentences like this do. Its easier to imagine things with it.
Its possible but so unlikely that impossible in reality.
You can also easy secure yourself, second address you own is risk with this slashed by half.

Which algorithm are you talking about? Addresses are not generated on blockchain. There is no algorithm that checks if a private key is already into use. There is no record of any private key on blockchain.

Also, one private key doesn't mean one wallet. One private key means one bitcoin address. The example you gave in which Bitcoin Address changes after each transaction is HD wallet which is generated using seed which is derived from mnemonic code and passphrase. I don't know why I am explaining at all, your bitcoin knowledge is horrendously wrong.

Even slight chances having the same private key still it will give doubt to the users. Who knows that out of luck your holdings will be shared to the same wallet private key. This is somehow what we call a really2x bad luck out of the so many private keys you two had made the same. LOL, anyway as it was mention from other usera that it is bwing close to impossible. Well just hope that the system will not going to make any duplications regarding with private keys so as to protect holdings and should not be to become the most unfortunate btc user.

This is a very good topic in my opinion, it would never thought to me if there really is a person who has the same private key as me.
This is a scary thing, that person can have full control over my wallets. Hopefully nothing happens to me. Occasionally someone's wallets
are hacked even though they already use maximum security, possibly that hacker having the same private key.

yup. good reminer. didnt know that way back when i set some some watch only wallets.. soon as i realized that i moved everything off to a new wallet.

True, but let's put some math to that for any newbies reading this who might be worried.

Let's say my online bank password is truly random and drawn from the full 95 character ASCII set. Something along the lines of c"AQ+K78[={2W+9t, for example. (In reality, this is significantly more secure than the VAST majority of passwords which are being used, but we will error on the side of caution.) If someone has 3 attempts, then the probability of them guessing my password is 3 out of 95¹⁶, which is a probability of 6.8*10^-32. Given that there are 2²⁵⁶ private keys, for someone to have the same probability of finding my private key, they would have to check 7.9*10⁴⁵ private keys. Even checking a trillion trillion keys every second, it would still take 250 trillion years for them to do so. I'm happy to take those chances.

Also worth pointing out that the chance of someone guessing your credit card PIN or even your long credit card number is astronomically more likely than either of the above scenarios.

It's always worth noting the caveat to this - if you have revealed your extended public key (as you might do when setting up a watch only wallet), then the additional knowledge of the private key of one single address in that wallet would allow an attacker to calculate all the private keys in that wallet.

yeah but also there are other ways of getting into your bank account that may not even involve using a login. after all your bank account is just an entry in a centralized database that can easily be hacked.
your bitcoin key still remains the same impossible to break key.

To clarify, I am still considering private key nearly impossible to bruteforce even if public key is known. Essentially, HD-wallets is simply more convenient way to "spread" coins across several addresses and also users don't have to back up each key. If someone finds one of your private keys (still impossible, but), he won't be able to steal an entire balance of HD-wallet.

HD wallets are not any significantly more secure as compared to the non HD wallet.

While it is true that a HD wallet allows you to have a higher entropy as compared to just bruteforcing addresses, the Bitcoin public key that is generated (ECDSA) already gives 128bits of entropy. That, by itself is sufficient enough. BIP32 allows you to go above and beyond that level but it is just redundant. It would be exponentially harder to bruteforce seeds with higher security but it doesn't offer a significant advantage over any keys that has >128bits of entropy.

except the bank will lock your online access after a set number of failed logins, typically three.

the only limit to how many guesses you can try for bitcoin private key is your computational power.

If anyone found precisely the same private key as yours, he would never deposit any bitcoins on the corresponding public address, thus he would never tend to keep it safe. The first thing he would do is withdraw existing balance to another address, over which he would have full control. So, if you still scared of someone finding your private key, use hierarchical deterministic wallets (HD-wallets) in which you will only have to keep a seed phrase that is used to derive private key/public key/address for each payment.

Yes, but if you make a transaction, the other guy will notice it.

Until now I have never encountered an event that has the same private key between one and another, in other words almost
impossible to happen. Let's just say that someone who has the same private key as I have, means that i can access his wallet
and vice versa. After all, if there is anyone who has the same private key, it is impossible for each other to know. Because
everyone keep a private key in a safe place, which is impossible for others to know.

I suppose when you think about it, the chances of someone randomly guessing your email and bank password are much higher than getting access to your BTC.  Email 30 characters max and passwords 6 to 16. That is a lot less combinations to try.

Thank you very much for the information. These articles are really very informative and answered me many of my questions, especially regarding the security of an ethereum wallet and the ability to have an individual personal key to access the wallet.

No, it is impossible. When generating keys, several levels of encryption and decryption are used. As well as guessing the key, the probability is almost zero.