Topic: How to Create a Bitcoin Address With Your Own Name (Read 197 times)

I am the one generating the vanity address, so pretty much by definition I will know what that vanity address is. So yes, it is bad for privacy and I can then link that address back to the person who requested it.

However, I can't imagine there are many people who are creating personalized vanity addresses to then keep them secret. If you start using an address such as bc1qpmalek, then you pretty much have zero privacy anyway.

Isn't that bad for privacy? You never had knowledge of the initial private key, but you know the other party's public key. And you use that public key as a base to generate a new one. That would give you the needed public information to track the address of that public key and know what the other person sends and receives. Maybe I am missing something obvious.   

In essence, all you need to do is add the public keys together.

Private keys are essentially just very large random numbers. Public keys are this random number multiplied by what is known as the generator point (G), which is a point on a curve with an X and Y coordinate. If I have the private key 5, my public key will be 5G. If you have the private key 10, your public key will be 10G. Adding our public keys together will give us 15G. Adding our private keys together will give us 15, which would then generate the public key 15G. In essence it is this simple.

The core feature of this curve that we are using (known as secp256k1), is that it is impossible to work out the private key from only knowledge of the public key. So when you give me your public key, all I need to do is find another public key which when added together produces an address with the prefix we are looking for. I then give you the private key I ended up with, and you add it to your private key. You end up with a new private key which generates the address in question.

The original private key you generate should be completely random and generated in a cryptographically secure way, as would be done by any good wallet software. You definitely shouldn't go about picking it yourself. It simply serves as a starting point for me to begin my brute force search.

At the end of this process, your key + my key = final key. Given that I only know my key, and I have no idea what your key or the final key is, then I am no closer to being able to guess the final key than I would be with no information at all. All I know is that some number plus my key equals some other number. If all I know is that x + 10 = y, there are infinite solutions to that equation.*

In terms of software to actually add the keys together for you (it's a bit more complex than a simple addition because we have to perform the calculation modulo n, with n being the order of the curve (essentially the number of valid points on the curve)) then you can use the links nc50lc has provided, or there is also this site: https://gobittest.appspot.com/

*For private keys, there would be n possible solutions, i.e. the same number as the number of all possible private keys.

LoyceV's "Pretty Addy Giveaway" thread has detailed instructions of an example of split key method.
The tool used in the instruction is bitaddress.
Link: https://bitcointalksearch.org/topic/pretty-addy-giveaway-part-2-1813624

Alternatively, you can do that solely in VanitySearch if you prefer that tool through -kp, -sp and then -rp commands.
However, it doesn't have a secure way to generate the initial keypair (it requires a passphrase which works like a brainwallet).

where/how i can combine those keys to form an totally different key, and the original secret private key will come from, or i need to chose numbers (in original secret private key ) by my own ?

Certainly. In essence, it works like this:

You generate key pair in private. You keep the private key secret and secure, and you give me the public key. I can then start a vanity search using your public key as a base. I find a corresponding key pair, such that when the public key of my key pair is combined with the public key that you have given me, the resulting public key generates an address with your chosen prefix.

I then give you the private key from the key pair I have generated. You can then combine this private key with your original secret private key to arrive at a new private key, which matches the combined public key and the vanity address as above.

The result is that you have your chosen vanity address, and you are the only person who knows the private key which generates this address. The knowledge of the partial key which I generated gives me absolutely zero additional information about the final key and does not weaken the security of your final key in the slightest.

Sorry for bothering you, but can you explain what "Split key method" means?
I'm still trying to learn most terms associated with crypto.




I surely may not know much about Bitcoin/crypto but I do know a little about privacy and security, and if you truly want to have fun then you should consider running the software yourself rather than using unsafe wallet address.

No. Absolutely do not do this.

You should never use any service in which someone else is responsible for generating or handling your raw private keys. There is absolutely nothing stopping the person who generates that key from simply waiting for you to use it and then stealing all your coins.

Given how easy it is to use the VanitySearch software linked to above, the best option is simply to do it yourself. If you can't, then use the split key method to have someone else trustlessly generate the address for you without ever knowing the private key. I'm happy to do this for anyone who is desperate for a vanity address.

You can use a vanity address generator like this one https://vanitygen.net/ but they are the ones generating your private key so they are not good for anything except for novelty use for tips, donations and other small payments.

I have the vanity address 1HoDLhXMf6RxGwGmV5DX61Mfg26K45L1x1 which has never received even a single payment but it's fun to have one and taking a dive to learn how addresses are generated can be a good learning experience.

That, and segwit addresses are faster to generate than legacy ones.

Literally nothing beyond cosmetics. And obviously they encourage address reuse, so really aren't a great idea at all. I suppose you could also create bc1qst0rage... or bc1qsalary... or whatever if you wanted instead of labeling your addresses locally, although that would be terrible for privacy.

I guess I underestimated the quality of certain software and the hardware capabilities home systems have nowadays. You know more about Bitcoin than most people on this forum. Besides the appearance and appeal of having your bitcoin address display o_e_l_e_o (or whatever else you want), what's the benefit of having one? 

If OP is planning to run the software himself, then VanitySearch is superior to VanityGen. It is far quicker, as well as supporting segwit vanity addresses rather than just legacy ones.

For segwit vanity addresses (because why is anyone still using legacy addresses?) I can do 8 characters in about 3 minutes on my home computer. Some quick testing shows it would take me about 3 days to have a 50% chance of finding 10 characters, but about 3 months to have a 50% chance of finding 11 characters. So 9 or 10 characters seems to be the limit of what is reasonable (depending on how long you are willing to run the software for).

You don't gain anything by using vanity addresses. They are just there for the esthetics. The number of unique characters also depends on the available computational power, but I don't think you can do more than 5 or 6. Everything else could perhaps take years to generate. I see it as an interesting experiment and something to play around with, but a waste of time overall.   

https://bitcointalksearch.org/topic/vanitysearch-yet-another-address-prefix-finder-5112311
or
https://bitcointalksearch.org/topic/vanitygen-vanity-bitcoin-address-generatorminer-v022-25804
or
https://bitcointalksearch.org/topic/1splitkeycom-the-easy-secure-and-mostly-free-vanity-wallet-service-closeddown-5397602

Keep in mind that you do give up privacy when you do this. If I know you are 1cafter6otQMbQWScA5AXnnDsRMeZeCh6 and you keep using that same address to send and receive I can better track you.

May or may not matter to you but it is something to keep in mind.

Even if you generate 100s of the 1cafter addresses it's still you.

-Dave

How to Create a Bitcoin Address With Your Own Name
like this: 1Adin6otQMbQWScA5AXnnDsRMeZeCh6ovu