Bitcoin Forum

Is it possible to create a Bitcoin Address using custom private key with Vanitygen?

So I can input a private key such as "supersecretprivatekey", and from that generate associated public address?

Why would you want to do that? It would be very insecure and not very useful.

Vanitygen isn't made for that, and there's currently no tool for that. There's a thread about "vanity private key" here (https://bitcointalk.org/index.php?topic=1273798.0), you might wanna read it.

Great thanks

bitaddress.org (http://bitaddress.org) is your answer

I don't believe there is an option there to use a custom private key as he asked.

Yes there is, under "wallet details"

You can enter a private key in format: WIF, WIFC, HEX, B64, B6, MINI, BIP38

For example, the private key for Base6 address "1425342302314253423023142534230231425342302314333323023142534230231425342302314 25342302314253423023"  is "5JMBJfgXCPpxB5HjiVJB4YvZ2wv4M6z3wqbTjtPqFKMCEC4E2jL"

I think that is close, but given what he wrote, doesn't seem to me to be what he is asking.  Maybe it is though.

I think what he wrote comes down to a brainwallet for which there is also an option under 'brain wallet'

edit:
The asociated public and private key for his "supersecretprivatekey" passphrase randomized with SHA256 are:
12f3na5TXRs4itNi9i1TCeSsXkny7A1hxp
5KHHB79dmtJHA5QfGXa5rtHdWDrx8EeiWPBaZM4o6frexXvmko6

I think that is closer to what he wants, but what he is really talking about is something like this:
5supersecretprivatekeyEeiWPBaZM4o6frexXvmko6

[quote author=cr1776 link=topic=1623960.msg16383348#msg16383348 date=1475001043
I think that is closer to what he wants, but what he is really talking about is something like this:
5supersecretprivatekeyEeiWPBaZM4o6frexXvmko6
[/quote]
Creating a valid private key isn't that hard. I'd have to look up how it works with the checksum, but it can be done.
What you could do, is edit the source from vanitygen in such a way that it only uses addresses that start with 5LoyceWasHere instead of random data. The second part of the key can be random and changed while searching for an address that starts with 1Loyce, and the last part of the key can be the checksum.

From http://directory.io/:
+ 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreB4AD8Yi
+ 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreBF8or94
+ 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreBKdE2NK

5 super secret private key space to randomize checksum

But as steven0021 said: it's insecure. And you can't even show off how cool the private key is, because that would make it even less secure. So it's useless.

Aha. I don't think it is possible because not all characters are allowed, just like with the bitcoin address.