Bitcoin Forum

Bitcoin => Bitcoin Discussion => Topic started by: steelboy on August 05, 2013, 08:03:46 PM



Title: Vanity Addresses
Post by: steelboy on August 05, 2013, 08:03:46 PM
I think i unerstand the concept of vanity addresses but I still am not sure on how long it will take and how much it will cost

Lets say i want 1xxxxxxx 

Any ideas? (Ballpark figure is ok)


Title: Re: Vanity Addresses
Post by: wopwop on August 05, 2013, 09:14:29 PM
1 million dollars


Title: Re: Vanity Addresses
Post by: J35st3r on August 05, 2013, 09:37:22 PM
Download a copy of vanitygen and try it out.

On a (pretty slow) laptop CPU ...

# vanitygen.exe 1xxxxxxx
Difficulty: 51529903411245
[82.48 Kkey/s][total 194304][Prob 0.0%][50% in 13.7y]

That's slow. GPU will go a lot faster (oclvanitygen.exe), but not on my laptop, so try it yourself.

With one less 'x' ...
# vanitygen.exe 1xxxxxx
Difficulty: 888446610538
[75.97 Kkey/s][total 243968][Prob 0.0%][50% in 93.8d]

And if you don't care about the case ...
# vanitygen.exe -i 1xxxxxx
Difficulty: 14102327151
[78.83 Kkey/s][total 245760][Prob 0.0%][50% in 1.4d]

Looking better  :)


Title: Re: Vanity Addresses
Post by: steelboy on August 05, 2013, 09:50:03 PM
Download a copy of vanitygen and try it out.

On a (pretty slow) laptop CPU ...

# vanitygen.exe 1xxxxxxx
Difficulty: 51529903411245
[82.48 Kkey/s][total 194304][Prob 0.0%][50% in 13.7y]

That's slow. GPU will go a lot faster (oclvanitygen.exe), but not on my laptop, so try it yourself.

With one less 'x' ...
# vanitygen.exe 1xxxxxx
Difficulty: 888446610538
[75.97 Kkey/s][total 243968][Prob 0.0%][50% in 93.8d]

And if you don't care about the case ...
# vanitygen.exe -i 1xxxxxx
Difficulty: 14102327151
[78.83 Kkey/s][total 245760][Prob 0.0%][50% in 1.4d]

Looking better  :)

13.7 years.  ;D I don't think i can wait that long.

I'll look at DLing vanitygen now. Is there a way to get people with faster computers to do it for me for money or does that mean they will get my private key?


Title: Re: Vanity Addresses
Post by: steelboy on August 05, 2013, 09:51:34 PM
Also, can it be done on a mac?


Title: Re: Vanity Addresses
Post by: J35st3r on August 05, 2013, 10:05:14 PM
Is there a way to get people with faster computers to do it for me for money or does that mean they will get my private key?

Google is your friend steelboy (or DuckDuckGo if google is not your friend) ...

https://en.bitcoin.it/wiki/Vanitygen answers both your questions (yes and yes, plus the speeds) and provides links.

Good luck, and be careful with those private keys, they are generated in plaintext so be sure your Mac is clean, and you'll need to import them into a wallet before you can use them.


Title: Re: Vanity Addresses
Post by: steelboy on August 05, 2013, 10:08:52 PM
Is there a way to get people with faster computers to do it for me for money or does that mean they will get my private key?

Google is your friend steelboy (or DuckDuckGo if google is not your friend) ...

https://en.bitcoin.it/wiki/Vanitygen answers both your questions (yes and yes, plus the speeds) and provides links.

Good luck, and be careful with those private keys, they are generated in plaintext so be sure your Mac is clean, and you'll need to import them into a wallet before you can use them.

I did check that page but it's pretty complicated. I went to the github page and downloaded the zip file. The folder is full of files with crazy extensions. Very confused.


Title: Re: Vanity Addresses
Post by: trout on August 05, 2013, 10:14:26 PM
a 7-letter word after 1 (e.g. 12345678) you can get mined for you fairly cheaply.
8 is more difficult/expensive, and the current record is 9.

3 or 4 letter words you can get yourself on your laptop's cpu in a matter
of minutes (4) or seconds (3)  after reading the "vanitygen" thread on the forums.


Title: Re: Vanity Addresses
Post by: steelboy on August 05, 2013, 10:21:17 PM
So i would need to be using a bitcoin client?

At present I just hold physical bitcoins and paper wallets

I would need to install Bitcoin qt?



Title: Re: Vanity Addresses
Post by: J35st3r on August 06, 2013, 07:46:56 AM
So i would need to be using a bitcoin client?
At present I just hold physical bitcoins and paper wallets
I would need to install Bitcoin qt?

There is no difference between using a paper wallet and a vanitygen address. In both cases you have a private key and the associated bitcoin address (if you print out your vanity address and private key, then you have created a paper wallet).

The vanity address creation services work rather differently from vanitygen as they employ a split-key (https://en.bitcoin.it/wiki/Split-key_vanity_address), and as I'm not an expert on this (though I am curious about how it works, so I'll be taking a look at it), I'll just refer you to the support thread https://bitcointalk.org/index.php?topic=84569.0


Title: Re: Vanity Addresses
Post by: gadman2 on August 06, 2013, 08:13:14 AM
7 characters is easy. I could probably hit one in a few minutes.


Title: Re: Vanity Addresses
Post by: westkybitcoins on August 06, 2013, 01:52:14 PM
Download a copy of vanitygen and try it out.

On a (pretty slow) laptop CPU ...

# vanitygen.exe 1xxxxxxx
Difficulty: 51529903411245
[82.48 Kkey/s][total 194304][Prob 0.0%][50% in 13.7y]

That's slow. GPU will go a lot faster (oclvanitygen.exe), but not on my laptop, so try it yourself.

With one less 'x' ...
# vanitygen.exe 1xxxxxx
Difficulty: 888446610538
[75.97 Kkey/s][total 243968][Prob 0.0%][50% in 93.8d]

And if you don't care about the case ...
# vanitygen.exe -i 1xxxxxx
Difficulty: 14102327151
[78.83 Kkey/s][total 245760][Prob 0.0%][50% in 1.4d]

Looking better  :)

13.7 years.  ;D I don't think i can wait that long.

I'll look at DLing vanitygen now. Is there a way to get people with faster computers to do it for me for money or does that mean they will get my private key?

You could check out SgtSpike's site, firstbitsrepo.com (http://firstbitsrepo.com).

Also, his thread regarding it:

https://bitcointalk.org/index.php?topic=182063.0/ (https://bitcointalk.org/index.php?topic=182063.0/)


Title: Re: Vanity Addresses
Post by: gadman2 on August 06, 2013, 04:27:26 PM
I would highly not recommend you use firstbitsrepo due to the ease of making a vanity address, especially those under 8 characters. My computer can generate any 7 character word in approx 2 hours. And about 5 days for any 8 character word. As for a 9, on the other hand, about 160 days.

I -really- don't want to knock him or anything, it's a honest service, but it's extremely overpriced. For example he has 1Acid vanity address for sale for 20$. Here's an example of how fast I can make a 1Acid address: http://www.gad.me/ss/20130806161938475.png I literately clicked start and that's how many I had in a matter of seconds... Could make about 10k addresses or more an hour if I use both cards... But honestly, his 8 character and 9 character prices are much more realistic. It would, in fact, take a very long time to find a 9 character address looking for one specific word.


Title: Re: Vanity Addresses
Post by: steelboy on August 06, 2013, 04:40:15 PM
I would highly not recommend you use firstbitsrepo due to the ease of making a vanity address, especially those under 8 characters. My computer can generate any 7 character word in approx 2 hours. And about 5 days for any 8 character word. As for a 9, on the other hand, about 160 days.

I -really- don't want to knock him or anything, it's a honest service, but it's extremely overpriced. For example he has 1Acid vanity address for sale for 20$. Here's an example of how fast I can make a 1Acid address: http://www.gad.me/ss/20130806161938475.png I literately clicked start and that's how many I had in a matter of seconds... Could make about 10k addresses or more an hour if I use both cards... But honestly, his 8 character and 9 character prices are much more realistic. It would, in fact, take a very long time to find a 9 character address looking for one specific word.

Thanks for that mate. I didn't realise you could do it that fast.

Regarding the split key generation. Is that completely safe? It all looks good but I want to be sure that it's 100% before going for it


Title: Re: Vanity Addresses
Post by: cp1 on August 06, 2013, 04:42:05 PM
Do you have a gpu?  Download oclvanitygen.


Title: Re: Vanity Addresses
Post by: gadman2 on August 06, 2013, 04:45:58 PM
I would highly not recommend you use firstbitsrepo due to the ease of making a vanity address, especially those under 8 characters. My computer can generate any 7 character word in approx 2 hours. And about 5 days for any 8 character word. As for a 9, on the other hand, about 160 days.

I -really- don't want to knock him or anything, it's a honest service, but it's extremely overpriced. For example he has 1Acid vanity address for sale for 20$. Here's an example of how fast I can make a 1Acid address: http://www.gad.me/ss/20130806161938475.png I literately clicked start and that's how many I had in a matter of seconds... Could make about 10k addresses or more an hour if I use both cards... But honestly, his 8 character and 9 character prices are much more realistic. It would, in fact, take a very long time to find a 9 character address looking for one specific word.

Thanks for that mate. I didn't realise you could do it that fast.

Regarding the split key generation. Is that completely safe? It all looks good but I want to be sure that it's 100% before going for it

I would say split key is safe.

And if you have any kind of GPU, you could make your own address under 7 characters fairly quick.


Title: Re: Vanity Addresses
Post by: steelboy on August 06, 2013, 05:16:43 PM
Afraid I don't have a gpu. Just a regular old laptop.

I've seen a couple of sites offering split key services. Anybody used any of them and can vouch for them?


Title: Re: Vanity Addresses
Post by: gadman2 on August 06, 2013, 05:32:06 PM
Tell me how to do the split key process and I'll make you one real quick :D. I'm familiar with the vanity gen, but not split key process.


Title: Re: Vanity Addresses
Post by: J35st3r on August 06, 2013, 06:49:48 PM
I did myself a quick test following the instructions on https://bitcointalk.org/index.php?topic=84569.0

Quote
An example (available from gobittest website):
We have a private key:
18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725
which maps to public key:
0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A 299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6

and say we want to find a pattern "166". One of the solutions takes a form of a private key
B18427B169E86DE681A1A62588E1D02AE4A7E83C1B413849989A76282A7B562F
mapping to public key:
049C95E0949E397FACCECF0FE8EAD247E6FD082717E4A4A876049FB34A9ADED110DFEA2EF691CC4 A1410498F4C312F3A94318CD5B6F0E8E92051064876751C8404

If we add the two public keys (like the person looking for the solution would do), we get a public key:
0436970CE32E14DC06AC50217CDCF53E628B32810707080D6848D9C8D4BE9FE461E100E705CCA98 54436A1283210CCEFBB6B16CB9A86B009488922A8F302A27487
which is equivalent to this address:
166ev9JXn2rFqiPSQAwM7qJYpNL1JrNf3h

If we add the two private keys (like the person requesting the address would), we get:
CA65722CD418ED28EC369E36CFE3B7F3CC1CD035BFBF6469CE759FCA30AD6D54
which maps to the same public key as the sum of the public keys, and thus - to the same address

Code:
I tested it ...

# vanitygen.exe -P 0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6 1Am
Difficulty: 1330
Pattern: 1Am
Address: 1AmZ7ZbCBj1JiPRrxVZhSAnayLLJ5MFfBQ
PrivkeyPart: 5JC5PMGVL9PkgLoWh4VJDHZTEgpZr8sAv2KwHG8uxjvLskKiZDt

Now use keyconv to combine, BUT it needs WIF not hex, so first convert using my script (or use https://bitaddress.org)
# python bitaddr_hexprompt.py
Enter hex: 18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725
5J1F7GHadZG3sCCKHCwg8Jvys9xUbFsjLnGec4H125Ny1V9nR6V  private key WIF

# keyconv -c 5J1F7GHadZG3sCCKHCwg8Jvys9xUbFsjLnGec4H125Ny1V9nR6V 5JC5PMGVL9PkgLoWh4VJDHZTEgpZr8sAv2KwHG8uxjvLskKiZDt
Address: 1AmZ7ZbCBj1JiPRrxVZhSAnayLLJ5MFfBQ
Privkey: 5JP2uw6ytF5pHXcYw4z5FYkJtEx8EFspXzXof9NAjwSfic8q2Du

IT WORKS!!

So if you wanted to do it, you need to have vanitygen installed on your computer (download the binaries, not the git if you're on windows)

First generate your private key in WIF format (I'm using keyconv here, but any other method will work).

# keyconv -G
Pubkey (hex): 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5
Privkey (hex): 621B77463A634509FFA0C8582E3909D00FC2076389AE9318848EED1A91AF0B58
Address: 14aZr9UxqxFnGFMesQsgAFtjXK2jKdbHoE
Privkey: 5JZVbnRV1gYky2rJ38RcpYVz74MewDRoH2m1a1JmDEBkAffePU6

Then you send gadman2 a PM with the public key ...

04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5

gadman2 does ...
oclvanitygen -P 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5 1xxxxxxxx

Which might come up with something like ...
# vanitygen -P 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5 1x
Difficulty: 1353
Pattern: 1x
Address: 1x4nfoivXG8UBjUzUkWtyPJDJ5cKBsjct
PrivkeyPart: 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3

He sends you the PrivkeyPart: 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3

And finally you combine with

# keyconv -c 5JZVbnRV1gYky2rJ38RcpYVz74MewDRoH2m1a1JmDEBkAffePU6 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3
Address: 1x4nfoivXG8UBjUzUkWtyPJDJ5cKBsjct
Privkey: 5KYJhKndXTgNGTN6RXTZZVr5VrNkxAoGpc4eK1UPyxqMYHyAzs5

And that's your private key and vanity address. Import it into a wallet and check that the address matches (or you can do this with https://bitaddress.org wallet details tab, which you can also download from github for offline use).

Test it out with something simple first before going all the way.

PS I hope I've got that right, just learning about it myself.


Title: Re: Vanity Addresses
Post by: steelboy on August 06, 2013, 07:21:32 PM
I did myself a quick test following the instructions on https://bitcointalk.org/index.php?topic=84569.0

Quote
An example (available from gobittest website):
We have a private key:
18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725
which maps to public key:
0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A 299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6

and say we want to find a pattern "166". One of the solutions takes a form of a private key
B18427B169E86DE681A1A62588E1D02AE4A7E83C1B413849989A76282A7B562F
mapping to public key:
049C95E0949E397FACCECF0FE8EAD247E6FD082717E4A4A876049FB34A9ADED110DFEA2EF691CC4 A1410498F4C312F3A94318CD5B6F0E8E92051064876751C8404

If we add the two public keys (like the person looking for the solution would do), we get a public key:
0436970CE32E14DC06AC50217CDCF53E628B32810707080D6848D9C8D4BE9FE461E100E705CCA98 54436A1283210CCEFBB6B16CB9A86B009488922A8F302A27487
which is equivalent to this address:
166ev9JXn2rFqiPSQAwM7qJYpNL1JrNf3h

If we add the two private keys (like the person requesting the address would), we get:
CA65722CD418ED28EC369E36CFE3B7F3CC1CD035BFBF6469CE759FCA30AD6D54
which maps to the same public key as the sum of the public keys, and thus - to the same address

Code:
I tested it ...

# vanitygen.exe -P 0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6 1Am
Difficulty: 1330
Pattern: 1Am
Address: 1AmZ7ZbCBj1JiPRrxVZhSAnayLLJ5MFfBQ
PrivkeyPart: 5JC5PMGVL9PkgLoWh4VJDHZTEgpZr8sAv2KwHG8uxjvLskKiZDt

Now use keyconv to combine, BUT it needs WIF not hex, so first convert using my script (or use https://bitaddress.org)
# python bitaddr_hexprompt.py
Enter hex: 18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725
5J1F7GHadZG3sCCKHCwg8Jvys9xUbFsjLnGec4H125Ny1V9nR6V  private key WIF

# keyconv -c 5J1F7GHadZG3sCCKHCwg8Jvys9xUbFsjLnGec4H125Ny1V9nR6V 5JC5PMGVL9PkgLoWh4VJDHZTEgpZr8sAv2KwHG8uxjvLskKiZDt
Address: 1AmZ7ZbCBj1JiPRrxVZhSAnayLLJ5MFfBQ
Privkey: 5JP2uw6ytF5pHXcYw4z5FYkJtEx8EFspXzXof9NAjwSfic8q2Du

IT WORKS!!

So if you wanted to do it, you need to have vanitygen installed on your computer (download the binaries, not the git if you're on windows)

First generate your private key in WIF format (I'm using keyconv here, but any other method will work).

# keyconv -G
Pubkey (hex): 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5
Privkey (hex): 621B77463A634509FFA0C8582E3909D00FC2076389AE9318848EED1A91AF0B58
Address: 14aZr9UxqxFnGFMesQsgAFtjXK2jKdbHoE
Privkey: 5JZVbnRV1gYky2rJ38RcpYVz74MewDRoH2m1a1JmDEBkAffePU6

Then you send gadman2 a PM with the public key ...

04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5

gadman2 does ...
oclvanitygen -P 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5 1xxxxxxxx

Which might come up with something like ...
# vanitygen -P 04069f08dd2b573cdf7b647236f11ba8c6020e83dae50d37cdeec3a63a4d0c092a3f20873cfbd6212754b763f9e477b14ea729db0176d80fa43f4beec9bd2024a5 1x
Difficulty: 1353
Pattern: 1x
Address: 1x4nfoivXG8UBjUzUkWtyPJDJ5cKBsjct
PrivkeyPart: 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3

He sends you the PrivkeyPart: 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3

And finally you combine with

# keyconv -c 5JZVbnRV1gYky2rJ38RcpYVz74MewDRoH2m1a1JmDEBkAffePU6 5Jo6gDpEbEhbZRu5RbUqq16DcPr2E6EZGPNQyBDP1cWFYMR4qh3
Address: 1x4nfoivXG8UBjUzUkWtyPJDJ5cKBsjct
Privkey: 5KYJhKndXTgNGTN6RXTZZVr5VrNkxAoGpc4eK1UPyxqMYHyAzs5

And that's your private key and vanity address. Import it into a wallet and check that the address matches (or you can do this with https://bitaddress.org wallet details tab, which you can also download from github for offline use).

Test it out with something simple first before going all the way.

PS I hope I've got that right, just learning about it myself.


Thing is that block I the middle of your response, with all the code, is like Latin to me. I literally have no idea what that means or how to interpret that.



Title: Re: Vanity Addresses
Post by: Yankee (BitInstant) on August 06, 2013, 07:29:05 PM
Here is a great app that works with any Java enabled computer and pretty basic to setup.

http://silverthreadsoftware.com/bitcoin/vanity/

http://silverthreadsoftware.com/bitcoin/vanity/screen.png

-Charlie


Title: Re: Vanity Addresses
Post by: J35st3r on August 06, 2013, 07:33:50 PM
Thing is that block I the middle of your response, with all the code, is like Latin to me. I literally have no idea what that means or how to interpret that.

Yeah, sorry, I've been kicking around computers for decades and tend to forget that other guys are not quite so comfortable with command line stuff.

If you've got a windows PC, I can try to guide you through it, but you mentioned a Mac earlier, and I can't really help with that (it should work pretty much the same way, but you may need to compile vanitygen from source - all those weird files you downloaded from github - and that I can't help there).

The general idea though is that you use the "keyconv" utility to create a private key and public key. Send the public key off to gadman2 who does the vanity address generation. He sands you back the part private key, and finally you use keyconv to combine your private key you generated in the first step (which never leaves your computer), with the part key to give the final vanity private key and address. You must never lose that final private key, so its best to import it right away into your wallet (and print it out for safekeeping too).



Title: Re: Vanity Addresses
Post by: gadman2 on August 06, 2013, 10:21:43 PM
Go to bitaddress.org
Click on vanity wallet
Click on generate in step one
Save the public key and private key
Pm me the public key and the prefix you want 
(7 letters or under ex: 1abcdefg)
Let me work my magic
I will pm you back a private key
Go to bitaddress.org
Click vanity wallet
Put my part key that I sent you in box 1 of step 2 and your first private key in box 2
Click calculate
Profit?!


Title: Re: Vanity Addresses
Post by: steelboy on August 06, 2013, 10:56:16 PM
Go to bitaddress.org
Click on vanity wallet
Click on generate in step one
Save the public key and private key
Pm me the public key and the prefix you want 
(7 letters or under ex: 1abcdefg)
Let me work my magic
I will pm you back a private key
Go to bitaddress.org
Click vanity wallet
Put my part key that I sent you in box 1 of step 2 and your first private key in box 2
Click calculate
Profit?!

I will do this tomorrow. :)


Title: Re: Vanity Addresses
Post by: Moogle on August 07, 2013, 02:27:55 AM
Here is a great app that works with any Java enabled computer and pretty basic to setup.

http://silverthreadsoftware.com/bitcoin/vanity/

http://silverthreadsoftware.com/bitcoin/vanity/screen.png

-Charlie

Looks nice. Will it use GPU?
I've tried on my GPU with oclvanitygen but just seem to get endless messages of nothingness. A GPU line then a CPU line.


Title: Re: Vanity Addresses
Post by: gadman2 on August 07, 2013, 02:29:44 AM
It doesn't do gpu mining.


Title: Re: Vanity Addresses
Post by: J35st3r on August 07, 2013, 07:51:35 AM
Go to bitaddress.org
Click on vanity wallet
Click on generate in step one
Save the public key and private key
Pm me the public key and the prefix you want 
(7 letters or under ex: 1abcdefg)
Let me work my magic
I will pm you back a private key
Go to bitaddress.org
Click vanity wallet
Put my part key that I sent you in box 1 of step 2 and your first private key in box 2
Click calculate
Profit?!

DOH! <facepalm> Yes, that works a charm. I was too fixated on vanitygen to even think it might already be built into bitaddress.org  :-[