[SOLVED]Really stupid question about offline address creation and the blockchain

[BrassicBob]

Ok, so I want to create a paper wallet. How does an address get created (BTC) on the blockchain, if you have no internet connection? I see it's possible, I just don't understand how it works, I'm missing something apparently - I see you can create literally thousands of addresses. What I don't get is how exactly they exist with no connection to the blockchain? are there millions of unused addresses out there?  

Thank you.

[1715642295]

1715642295

[1715642295]

1715642295

[1715642295]

1715642295

[achow101]

Ok, so I want to create a paper wallet. How does an address get created (BTC) on the blockchain, if you have no internet connection? I see it's possible, I just don't understand how it works, I'm missing something apparently - I see you can create literally thousands of addresses. What I don't get is how exactly they exist with no connection to the blockchain? are there millions of unused addresses out there? 

Thank you.

There is nothing about creating addresses that is like "registering" on the blockchain nor are they "assigned" by the blockchain. You generate addresses by generating a random number (the private key) and then manipulating that with hashes to get to the address. This is done offline. Technically every single address ever already exist, people just need to guess the private key for the address.

[BrassicBob]

There is nothing about creating addresses that is like "registering" on the blockchain nor are they "assigned" by the blockchain. You generate addresses by generating a random number (the private key) and then manipulating that with hashes to get to the address. This is done offline. Technically every single address ever already exist, people just need to guess the private key for the address.

Ok, thanks, that is helpful. However. To take your explanation one step further - Does that mean I could theoretically "see" a public address already existing on, say... blockchain.info, before it was technically ever generated offline?

That's the part I don't get. How is the address visible on these sites if the address was created offline? I can't see how they could already be there, that would a lot of data right? Thanks again and sorry for still trying to understand!  

[achow101]

Ok, thanks, that is helpful. However. To take your explanation one step further - Does that mean I could theoretically "see" a public address already existing on, say... blockchain.info, before it was technically ever generated offline?

That's the part I don't get. How is the address visible on these sites if the address was created offline? I can't see how they could already be there, that would a lot of data right? Thanks again and sorry for still trying to understand!  

Yes, you can see every single possible address. These are visible because nothing an address does requires it to be "registered" onto the blockchain. An address is a special encoding of the RIPEMD160 hash of a SHA256 hash. To computers, these hashes are simply really big integers. Because we know the size of a RIPEMD160 hash (160 bits), we know what the biggest number that it can represent. This happens to be 2^160. Thus every address is already known because we know what all of the numbers between 0 and 2^160 are and can thus get the address without ever knowing the private key.

[BrassicBob]

Yes, you can see every single possible address. These are visible because nothing an address does requires it to be "registered" onto the blockchain. An address is a special encoding of the RIPEMD160 hash of a SHA256 hash. To computers, these hashes are simply really big integers. Because we know the size of a RIPEMD160 hash (160 bits), we know what the biggest number that it can represent. This happens to be 2^160. Thus every address is already known because we know what all of the numbers between 0 and 2^160 are and can thus get the address without ever knowing the private key.

Ah... Ok.. Thanks, now I get it, the maths now make sense, thank you for that! Locking topic now thanks.