I lack knowledge pls guide me

[Charles-Tim]

In short, to answer OP's original question: Yes, it is theoretically possible for your wallet to generate an already used address, but our sun will have engulfed the Earth long before that ever happens.

I like this explanation, theoretically possible, but not possible during human existence.

How about the 4 extra bits added during checksum, is this not providing any security, like adding more impossibilities for the already existing seed phrase to again be generated by another users which is refered by some people as collision? I have noticed what people concentrate more on about this is the 128 bits of entropy.

[1714719520]

1714719520

[o_e_l_e_o]

How about the 4 extra bits added during checksum, is this not providing any security

No, the 4 bit checksum does not provide any extra security in this sense.

The 4 bit checksum is generated deterministically from the 128 bit entropy. The same 128 bits of entropy will always produce the same 4 bit checksum. So although a 12 word BIP39 seed phrase does encode 132 bits of data, there are not 2¹³² possible valid seed phrases. For every 132 bit seed phrase, there are 2⁴ possible combinations of the 4 bit checksum, but only one of them will be valid. Given that, 2¹³² / 2⁴ = 2¹²⁸.

If you want more than 128 bits of entropy in your BIP39 seed phrase, then you need to use more than 12 words, with the most common alternative being 24 words, which provides 256 bits of security with an 8 bit checksum. Note that as I said above, however, your private keys generated from a 24 word seed phrase still "only" have 128 bits of security.

[NeuroticFish]

If you want more than 128 bits of entropy in your BIP39 seed phrase, then you need to use more than 12 words, with the most common alternative being 24 words, which provides 256 bits of security with an 8 bit checksum. Note that as I said above, however, your private keys generated from a 24 word seed phrase still "only" have 128 bits of security.

May be stupid question, still:
What if the private key is not generated from a seed phrase? What if the private key is just one random (may need better word here) number in the range of valid private keys? Would this provide the same 128 bits? Can't we reach 160? Or I'm confusing something?

[o_e_l_e_o]

It's a good question. The answer will always be 128 bits at most (obviously it's possible to generate a less secure key if you use a brain wallet, poor source of entropy, etc.)

Bitcoin uses the secp256k1 curve. The parameters of this curve state that all private keys will be 256 bits in length, but will provide 128 bits of security. This is because the most efficient way to attack a private key is to attempt to solve the ECDLP, which requires 2¹²⁸ operations.

It is not the method of generating private keys that limits them to 128 bits of security. Rather, it is intrinsic to the elliptic curve bitcoin is based on.

This can be seen in Standards for Efficient Cryptography. SEC 2: Recommended Elliptic Curve Domain Parameters. (Table at the bottom of page 4.)

[iamsheikhadil]

No, you are safe when it comes to generating new addresses lol, every wallet has basically two features, one is the public and the other is the private key and they are all very random and since all wallets are integrated to blockchain itself, it would never be possible for a generation of wallet which matches exactly the same which has all the same information and stuffs, the odds are astronomically low, or I would say, impossible! 

[o_e_l_e_o]

one is the public and the other is the private key and they are all very random

The series of digits in each private key may be random, but the private keys themselves are not random - they are generated deterministically from your seed phrase.

and since all wallets are integrated to blockchain itself, it would never be possible for a generation of wallet which matches exactly the same which has all the same information and stuffs

I'm not sure what you mean here. There is no "integration" between a wallet and the blockchain. It is entirely possible to create and use a wallet which is entirely airgapped and never once connects to the internet, and so the network would have no idea of its existence. There is absolutely nothing at a protocol level or within the blockchain itself which prevents you from generating the exact same wallet as someone else. The thing which prevents this is the incomprehensible size of the numbers we are dealing with.

[witcher_sense]

and since all wallets are integrated to blockchain itself, it would never be possible for a generation of wallet which matches exactly the same which has all the same information and stuffs

I'm not sure what you mean here. There is no "integration" between a wallet and the blockchain.

Perhaps, the "integration" means that wallets only create such keys and addresses that can be recognized by the network and which it considers valid to deal with. In other words, if a key or an address fails to meet a certain standard or format, it will not and cannot be "integrated" into the network.

It is entirely possible to create and use a wallet which is entirely airgapped and never once connects to the internet, and so the network would have no idea of its existence.

Either it is inaccurate or I misunderstood the point you make. The network will have an idea about the existence of an air-gapped wallet that has never touched the Internet if some of the addresses the wallet controls have been associated with transactions that either were already confirmed by the network or are still sitting in a mempool.

[o_e_l_e_o]

The network will have an idea about the existence of an air-gapped wallet that has never touched the Internet if some of the addresses the wallet controls have been associated with transactions that either were already confirmed by the network or are still sitting in a mempool.

Only when an address sends coins out can we say for sure that someone has created a wallet with the associated private key. I can generate millions of private keys and associated addresses offline without the network having any idea I am doing so. Similarly, I can send coins to any address I like, including one I've just made up and which the associated private key is unknown. Not only does the wider network not care, but indeed the wider network has absolutely no way of knowing. There is no "integration" between wallet and network in this manner, where the network somehow checks the addresses you have generated to make sure no one else has used them first or they do indeed have a known private key. The network doesn't even care if you send coins to unspendable outputs. All it cares about is that your transactions are valid.

[Cuda911]

Thanks for all your responses everyone there is surely a whole lots of things u learned just reading through every comments on here, thanks.

[Rruchi man]

Don't turn me into a laughing stock I'm just trying to understand what I don't know...

I totally love the motive behind OP's discuss, a pure desire and intent to learn and become better. It is with such a desire that knowledge quickly comes to someone. Rather than pretending to know, you have humbled yourself to ask what you do not know. I think such an attitude is merit deserving and should be emulated by others as well. I will definitely revisit this your post to encourage you with a merit as soon as i get to give.

[Pterosaur]

Nope it's impossible  I guess this is what makes some newbies to start importing recovery seeds they see online into iancoleman website maybe they can hit the jackpot but in the end they got served by getting scammed themselves.. not accusing just saying.

[Lordhermes]

If you lack knowledge on a particular field,the best thing to do is to look for someone that is more experienced on that field,and seek for knowledge or advice on the course that you need.So many people neglect looking for the right people to guild them,and conclude that that course was not meant for them.
Every man should have a role model in life,someone that guilds them when they are in the wrong part.
So the best answer to you is to research or look for someone that is in the right position of rendering advice on the field that you need advice on,Atleast that will be the best for you.

[cointalkzz]

Being a beginner I'm not well versed in all activities related to forum.My moto is to gain maximum knowledge by reading variety of informations shared in the site.I wish to know more about wallet,how to invest,though invested whether it's safe or not. likely how to put a quality post.Adding links will it worth it like lots of doubts is been emerging as time pass by. Lacking knowledge initially is not remarkable instead without any efforts makes the thing noted.

[Pmalek]

Being a beginner I'm not well versed in all activities related to forum.My moto is to gain maximum knowledge by reading variety of informations shared in the site.I wish to know more about wallet,how to invest,though invested whether it's safe or not. likely how to put a quality post...

Read all the posts in this thread and you will gain some knowledge about how wallets work, how your seed is generated, what address collisions are, and how unlikely they are to happen.

After that, navigate to the beginning of the Beginners & Help board and check out the sticky threads. There is a thread dedicated to newbies written by Lauda, read that. Read Lauda's other thread about wallets (also a sticky thread).
Go to the Meta board and read the rules of the forum. There should be a link to the rules in Lauda's beginner thread as well. You need to know what you can and can't do around here.

I can recommend checking out Beginners & Help Encyclopedia [UPD: +Electrum Board.]
It's a huge list of everything you could possibly need. Bookmark it and go through the topics that you are interested in.

And generally, it's always a good idea to create your own threads when asking questions instead of hijacking someone else's. A little tip for the future.
Good luck and enjoy your stay!

[YellowSwap]

That's impossible but not a stupid question because many newbies don't know this, I've never witnessed any recovery seed having the same word phrases with another recovery seed no matter how many new wallets you creates.