Custom Bitcoin Addresses?

[LTCMINER2013]

http://www.ebay.ie/itm/Custom-Bitcoin-Address-4-letter-/261226849404?pt=US_World_Coins&hash=item3cd255647c#ht_948wt_1151

Is this possible?

[NoBit]

https://en.bitcoin.it/wiki/Vanitygen

[NoBit]

Be aware that if you buy from this unknown person you will most likely be scammed when you put BTC into the address, because he will have your private key, no matter what he says.

Generate the address yourself!

[mprep]

Be aware that if you buy from this unknown person you will most likely be scammed when you put BTC into the address, because he will have your private key, no matter what he says.

Generate the address yourself!

Though that doesn't seem stop the huge amount of merchants selling even more and more of them. Not sure if people buy them though.

[Kluge]

Be aware that if you buy from this unknown person you will most likely be scammed when you put BTC into the address, because he will have your private key, no matter what he says.

Generate the address yourself!

Though that doesn't seem stop the huge amount of merchants selling even more and more of them. Not sure if people buy them though.

Should always be regarded as a scam. These aren't hard to generate. You can get a 2-4 letter identifier in an address with a CPU within a day or two, and 2-8 characters with a modern GPU. More than 8 characters generally requires a lot being thrown at it, though. Aside from the huge scam potential, the amount requested on the site is exploitative.

[mprep]

Be aware that if you buy from this unknown person you will most likely be scammed when you put BTC into the address, because he will have your private key, no matter what he says.

Generate the address yourself!

Though that doesn't seem stop the huge amount of merchants selling even more and more of them. Not sure if people buy them though.

Should always be regarded as a scam. These aren't hard to generate. You can get a 2-4 letter identifier in an address with a CPU within a day or two, and 2-8 characters with a modern GPU. More than 8 characters generally requires a lot being thrown at it, though. Aside from the huge scam potential, the amount requested on the site is exploitative.

Really? Haven't tried it. Maybe I should.

[Kluge]

Be aware that if you buy from this unknown person you will most likely be scammed when you put BTC into the address, because he will have your private key, no matter what he says.

Generate the address yourself!

Though that doesn't seem stop the huge amount of merchants selling even more and more of them. Not sure if people buy them though.

Should always be regarded as a scam. These aren't hard to generate. You can get a 2-4 letter identifier in an address with a CPU within a day or two, and 2-8 characters with a modern GPU. More than 8 characters generally requires a lot being thrown at it, though. Aside from the huge scam potential, the amount requested on the site is exploitative.

Really? Haven't tried it. Maybe I should.

Yeah. Maybe I'm just stupid, but it always takes me 5-10 times to get the VanityGen settings right in command line, and I forget in what order I need it to be in each time I want to generate something.

Just make sure you're using the ocl variant and are using the GPU to generate or else you'll be sitting around for a LONG time unless it's 2-3 characters long. Doing case-insensitive generation saves a TON of time, too. I believe there's a version out working for Avalon FPGAs, now.... or maybe that was a dream.... There is supposedly a vanitygen pool somewhere which I guess is able to generate the privkey without the miner knowing it (or maybe he does) -- I haven't looked into it.

[jackjack]

Actually, it is possible for someone else to create a vanity address for you without having the private key
It's just some basic EC maths

[mprep]

Actually, it is possible for someone else to create a vanity address for you without having the private key
It's just some basic EC maths

How?

[jackjack]

Actually, it is possible for someone else to create a vanity address for you without having the private key
It's just some basic EC maths

How?

A wants a vanity address, B owns 1000000 GPUs:

• 1. A choses a private key pvk1
• 2. He calculates the public key from it, pbk1
• 3. He sends it to B
• 4. B uses it as a starting point for calculations: pbk2 = pbk1, pvk2 = 0
• 5. If pbk2 fulfills the criterion of A, then goto 8., else goto 6.
• 6. B adds G (the secp256k1 generator) to pbk2, and adds 1 to pvk2
• 7. Goto 5.
• 8. B sends pvk2 to A
• 9. A can now calculate the real private key, which is pvk1+pvk2

[mprep]

Actually, it is possible for someone else to create a vanity address for you without having the private key
It's just some basic EC maths

How?

A wants a vanity address, B owns 1000000 GPUs:

• 1. A choses a private key pvk1
• 2. He calculates the public key from it, pbk1
• 3. He sends it to B
• 4. B uses it as a starting point for calculations: pbk2 = pbk1, pvk2 = 0
• 5. If pbk2 fulfills the criterion of A, then goto 8., else goto 6.
• 6. B adds G (the secp256k1 generator) to pbk2, and adds 1 to pvk2
• 7. Goto 5.
• 8. B sends pvk2 to A
• 9. A can now calculate the real private key, which is pvk1+pvk2

Could you explain step six? Where and how do you add it. If you can, provide some real or made up examples.

[RichG]

http://www.ebay.ie/itm/Custom-Bitcoin-Address-4-letter-/261226849404?pt=US_World_Coins&hash=item3cd255647c#ht_948wt_1151

Is this possible?

SCAM

[LTCMINER2013]

i know letting someone do it, is probably not a good idea.  but i got the answer i wanted in that there is software to try get one

[jackjack]

Actually, it is possible for someone else to create a vanity address for you without having the private key
It's just some basic EC maths

How?

A wants a vanity address, B owns 1000000 GPUs:

• 1. A choses a private key pvk1
• 2. He calculates the public key from it, pbk1
• 3. He sends it to B
• 4. B uses it as a starting point for calculations: pbk2 = pbk1, pvk2 = 0
• 5. If pbk2 fulfills the criterion of A, then goto 8., else goto 6.
• 6. B adds G (the secp256k1 generator) to pbk2, and adds 1 to pvk2
• 7. Goto 5.
• 8. B sends pvk2 to A
• 9. A can now calculate the real private key, which is pvk1+pvk2

Could you explain step six? Where and how do you add it. If you can, provide some real or made up examples.

I'll be able to post examples in an hour
Until then: http://en.m.wikipedia.org/wiki/Elliptic_curve_point_multiplication#Point_addition

[jackjack]

i know letting someone do it, is probably not a good idea. 

Did you even read post #8?

[LTCMINER2013]

i did, and i understand it.  but the guy on ebay didnt say he will do it like this so .. thats the issue

edit :   oh he did mention "keypart"  sorry

[bitbybit2]

http://www.ebay.ie/itm/Custom-Bitcoin-Address-4-letter-/261226849404?pt=US_World_Coins&hash=item3cd255647c#ht_948wt_1151


Is this possible?

It is possible and you will see that it is for free. Just search gibiru.com for bitcoin address generator. You can click vanity address button. And Voila an address and a private key. You have bitcoin address with private key.

[jackjack]

http://christelbach.com/ECCalculator.aspx

Parameters here: https://en.bitcoin.it/wiki/Secp256k1
mod p = 115792089237316195423570985008687907853269984665640564039457584007908834671663
A = 0
B = 7
Gx = 55066263022277343669578718895168534326250603453777594175500187360389116729240
Gy = 32670510020758816978083085130507043184471273380659243275938904335757337482424


(Doesn't look really acurate though)

[jackjack]

Q&D python code for vanity address mining
You can put it in pywallet (or jeeq or jasvet, I don't really know which one have the correct classes. PM me if you want to test)
You just need to change pvk1 and pattern

Code:

verbose=False

#### On A's computer
pvk1=2142
key=EC_KEY(pvk1)
print 'Hidden pvk1: %d'%pvk1
print 'pbk1 X: ', key.pubkey.point.x()
print 'pbk1 Y: ', key.pubkey.point.y()
print

#### B receives X and Y and puts them in pbk2
pbk2=key.pubkey.point
pvk2=0
pattern='1BTC'
print 'Pattern: '+pattern
while True:
        pvk2+=1
        pbk2=pbk2.__add__(key.generator)
        if verbose:
                print 'Partial private key pvk2=%d'%pvk2
                print 'pbk2 X: ', pbk2.x()
                print 'pbk2 Y: ', pbk2.y()
                print 'pbk2   compressed addr: ', pbk2.get_addr(True)
                print 'pbk2 uncompressed addr: ', pbk2.get_addr(False)
                print
        if pbk2.get_addr(True)[:len(pattern)]==pattern:
                break
        if pbk2.get_addr(False)[:len(pattern)]==pattern:
                break

#### B sends pvk2 to A
finalpvk=pvk1+pvk2
print 'My hidden pvk1: %d'%pvk1
print 'Received pvk2:  %d'%pvk2
print 'Final pvk:      %d'%finalpvk

key=EC_KEY(finalpvk)
if key.pubkey.point.get_addr(True)[:len(pattern)]==pattern:
        print 'BitcoinAddress(pvk=%d, compressed=True)  ='%finalpvk, key.pubkey.point.get_addr(True)
elif key.pubkey.point.get_addr(False)[:len(pattern)]==pattern:
        print 'BitcoinAddress(pvk=%d, compressed=False) ='%finalpvk, key.pubkey.point.get_addr(False)
else:
        print "pvk2 doesn't work"

For pvk=2142 and pattern='1jj'

Hidden pvk1: 2142
pbk1 X:  65150968730280697562609886764166998172449505192100168981244287450372694995242
pbk1 Y:  71888227149264242494450017634314194438151153455233498547016746414353185433649

Pattern: 1jj
My hidden pvk1: 2142
Received pvk2:  2570
Final pvk:      4712
BitcoinAddress(pvk=4712, compressed=True)  = 1jjenYCokb9eHC2Sg82Q13dyY6YHb3BRX

For pvk=2142 and pattern='1BTC'

Hidden pvk1: 2142
pbk1 X:  65150968730280697562609886764166998172449505192100168981244287450372694995242
pbk1 Y:  71888227149264242494450017634314194438151153455233498547016746414353185433649

Pattern: 1BTC
My hidden pvk1: 2142
Received pvk2:  35640
Final pvk:      37782
BitcoinAddress(pvk=37782, compressed=False) = 1BTCHcadnBqGqCRco6vDyMpm5KMN16QT6e