Custom Bitcoin address ?

[unick]

I saw that a few times on blockchain.info and now with the kaperlescoin...

how is it possible to have these "custom" addresses on the bitcoin network ?

3KARPE1ESwHERE1SoUrMoNEYxxxx8dXeC5

[skooter]

I saw that a few times on blockchain.info and now with the kaperlescoin...

how is it possible to have these "custom" addresses on the bitcoin network ?

3KARPE1ESwHERE1SoUrMoNEYxxxx8dXeC5

It's easy to generate a public key.

Nobody has the private to key to that though, so any coins sent to that address are not spendable.

https://blockchain.info/address/1FuckMtGoxFFFFFFFUUUUUUUUUUQXW5ik

[unick]

well maybe no one can spend the coins in those addresses.

but take a look here

https://blockchain.info/tags

lots of custom addresses

just a few from that page

1Coffee9ev4XQ5krwdGtkdUzvzXN3EpFna
1Bet12kCPomyc35y5Lt99ZNnAr2pC66dqw
1BTC11ifbnvoWY8RJ28nDhZ1SDtj8ooE6a
1MoneySKsyZewy9c7wPyWdX7j6Lxgfazdc
1GERSLqHqpGBGpSFf1UTcH7LfVxWxA4mgC


and more!

They have the money to spend those and they all have a connection to what they are used for

[skooter]

well maybe no one can spend the coins in those addresses.

but take a look here

https://blockchain.info/fr/tags

lots of custom addresses

just a few from that page

1Coffee9ev4XQ5krwdGtkdUzvzXN3EpFna
1Bet12kCPomyc35y5Lt99ZNnAr2pC66dqw
1BTC11ifbnvoWY8RJ28nDhZ1SDtj8ooE6a
1MoneySKsyZewy9c7wPyWdX7j6Lxgfazdc
1GERSLqHqpGBGpSFf1UTcH7LfVxWxA4mgC


and more!

They have the money to spend those and they all have a connection to what they are used for

You can generate short custom addresses. This one is mine:

https://blockchain.info/address/1Niggerw15VezU6rA7jRBuJt9ceg9VL1jh

Took 15 minutes of GPU time to generate.

[grifferz]

It's possible to "mine" private keys to look for ones with a desired string in them, but for more than 7 or so specific characters that gets computationally infeasible, so if you see ones like that then yes they are most likely invented and coins sent to them will be lost.

[unick]

well maybe no one can spend the coins in those addresses.

but take a look here

https://blockchain.info/fr/tags

lots of custom addresses

just a few from that page

1Coffee9ev4XQ5krwdGtkdUzvzXN3EpFna
1Bet12kCPomyc35y5Lt99ZNnAr2pC66dqw
1BTC11ifbnvoWY8RJ28nDhZ1SDtj8ooE6a
1MoneySKsyZewy9c7wPyWdX7j6Lxgfazdc
1GERSLqHqpGBGpSFf1UTcH7LfVxWxA4mgC


and more!

They have the money to spend those and they all have a connection to what they are used for

You can generate short custom addresses. This one is mine:

https://blockchain.info/address/1Niggerw15VezU6rA7jRBuJt9ceg9VL1jh

Took 15 minutes of GPU time to generate.

lol, nice

but the question is still how?

you let your gpu run on a script for 15 minute and you found that one ?

[skooter]

well maybe no one can spend the coins in those addresses.

but take a look here

https://blockchain.info/fr/tags

lots of custom addresses

just a few from that page

1Coffee9ev4XQ5krwdGtkdUzvzXN3EpFna
1Bet12kCPomyc35y5Lt99ZNnAr2pC66dqw
1BTC11ifbnvoWY8RJ28nDhZ1SDtj8ooE6a
1MoneySKsyZewy9c7wPyWdX7j6Lxgfazdc
1GERSLqHqpGBGpSFf1UTcH7LfVxWxA4mgC


and more!

They have the money to spend those and they all have a connection to what they are used for

You can generate short custom addresses. This one is mine:

https://blockchain.info/address/1Niggerw15VezU6rA7jRBuJt9ceg9VL1jh

Took 15 minutes of GPU time to generate.

lol, nice

but the question is still how?

you let your gpu run on a script for 15 minute and you found that one ?

it's a program called oclvanitygen

It's possible to "mine" private keys to look for ones with a desired string in them, but for more than 7 or so specific characters that gets computationally infeasible, so if you see ones like that then yes they are most likely invented and coins sent to them will be lost.

I can realistically do 8 characters (case sensitive) or 11 characters (not case sensitive), but those will take quite some time to do (a month)

7 characters (case sensitive) would take under 1 day.

[unick]

It's possible to "mine" private keys to look for ones with a desired string in them, but for more than 7 or so specific characters that gets computationally infeasible, so if you see ones like that then yes they are most likely invented and coins sent to them will be lost.

is there a script available somewhere to "mine" those addresses ?

edit: just saw your link, thanks. I'll have a look

[grifferz]

but the question is still how?

you let your gpu run on a script for 15 minute and you found that one ?

Vanitygen for example:

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

Same principle as mining for bitcoins.

Though a rather more niche market.

[unick]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

[grifferz]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

Hack how? Ask a more specific question.

[TookDk]

lol, nice

but the question is still how?

you let your gpu run on a script for 15 minute and you found that one ?

This python script works great to generate a pair of puplic/private adr:
https://bitcointalk.org/index.php?topic=361092.msg3866429#msg3866429

It should not be too hard to modify the script to run in a loop and search for a puplic key containing e.g. "unick".
By allowing both upper and lower case, you greatly reduce the time to find the private key.

[zolace]

Websites such as BitcoinVanity will let you generate a custom prefix right in your browser. While this is incredibly convenient, you have to trust websites like these to not save your private keys. Furthermore, online vanity address generators may charge a fee, depending on the length of the prefix. If you feel that you can trust such an online service and have no issue paying for a custom Bitcoin address, then go ahead. But if you’d rather put in a bit of extra effort to get a FREE and SECURE address

[TookDk]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

No absolutely not (if you have generated the private key on a offline computer with your own program, and used a good random algorithm)

(brainwallets are "easy" to hack, but that is a completely different story).

As long as your search random (at least as random as your computer allows you) for your public key, then is the chance very small for someone to find the same private key.

When that is said: I am personally very paranoid about my long-term storage private keys, they are all created with physical die's, to avoid the pseudo randomness that all computers have.  

[Bitcoin Magazine]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

No absolutely not (if you have generated the private key on a offline computer with your own program, and used a good random algorithm)

(brainwallets are "easy" to hack, but that is a completely different story).

As long as your search random (at least as random as your computer allows you) for your public key, then is the chance very small for someone to find the same private key.

When that is said: I am personally very paranoid about my long-term storage private keys, they are all created with physical die's, to avoid the pseudo randomness that all computers have.  

so all i'd have to do is hack your place and time (i.e. take a picture of you rolling the dice, then do a SHA-224 sum of the file) and plug that in the brainwallet

[unick]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

Hack how? Ask a more specific question.

by hack, I meant how likely is someone to find the correct private key given the public key with that generator

[skooter]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

Hack how? Ask a more specific question.

by hack, I meant how likely is someone to find the correct private key given the public key with that generator

Zero

[grifferz]

by hack, I meant how likely is someone to find the correct private key given the public key with that generator

If you mean, how likely is it that someone could generate a private key that matches an already existing and in-use bitcoin address that has funds in it, then the answer is:

Astronomically small, so small that there probably isn't enough energy in the known universe to power the hardware needed to do it.

[unick]

by hack, I meant how likely is someone to find the correct private key given the public key with that generator

If you mean, how likely is it that someone could generate a private key that matches an already existing and in-use bitcoin address that has funds in it, then the answer is:

Astronomically small, so small that there probably isn't enough energy in the known universe to power the hardware needed to do it.

lol.

it's just that here https://en.bitcoin.it/wiki/Vanitygen

they is it took 10 seconds to generate this key pair...
so if I try to generate an address with that smame prefix, woulnd't i get the same private key?

Code:

$ ./vanitygen 1Boat
Difficulty: 4476342
Pattern: 1Boat                                                                 
Address: 1BoatSLRHtKNngkdXEeobR76b53LETtpyT
Privkey: 5J4XJRyLVgzbXEgh8VNi4qovLzxRftzMd8a18KkdXv4EqAwX3tS

given I have not read thoroughly, and I assume that I can set a higher difficulty to make it harder to find but it made me wonder.

[TookDk]

what's the chances someone could hack those custom addresses (or any other addreses for that matter)

No absolutely not (if you have generated the private key on a offline computer with your own program, and used a good random algorithm)

(brainwallets are "easy" to hack, but that is a completely different story).

As long as your search random (at least as random as your computer allows you) for your public key, then is the chance very small for someone to find the same private key.

When that is said: I am personally very paranoid about my long-term storage private keys, they are all created with physical die's, to avoid the pseudo randomness that all computers have.  

so all i'd have to do is hack your place and time (i.e. take a picture of you rolling the dice, then do a SHA-224 sum of the file) and plug that in the brainwallet

Yes, absolutely.