Safe vanity addresses through key merging

Safe vanity addresses through key merging
“Vanity”. Image by Rob oo via Flickr.com. License: Creative Commons

Vanity addresses are Bitcoin addresses with certain, self-selected character combinations. Actually, you have to have these addresses calculated by your own computer. Bitcoin university.DE offers to make them safe for others. We look at how it works – and whether it is really safe.

Vanity addresses are “special addresses” for Bitcoin and other cryptocurrencies: addresses that, as the name suggests. For example 1Bergmannpfqzwalmre8ghjqghtefd3xMW – my very personal address.

Such vanity addresses can be “mine” by having your computer generate addresses until the right one is included. Depending on the length of the letter chain you want, this can take a few minutes to a few years. I have already written here about the fascinating math behind it, when a special address from the ocean of infinity.

Today I would like to introduce you to a Bitcoin University service: the Vanity Address Generator.

Not everyone wants to calculate a vanity address on their own computer. Be it because the software is too unwieldy for it, be it because your own computer is not strong enough, or be it because you don’t want the mill to be rattled for 18 days. However, one should not entrust the calculation of the vanity address to a service provider. Because if you calculate the address, you also have the private key. And a private key that someone else has is worthless, or, if you do not know the problem, more worthless than worthless.

It is clear, and can’t be any different: you either generate the Vanity address yourself or not at all. Or?

As so often, cryptography makes things possible that you don’t normally imagine. The Bitcoin-Univers team has implemented a procedure in which you can safely have someone else found the address.

The trick is the so -called “Address Merging”, which means in German to merge addresses: one connects two addresses or. Public key to generate a new address. In this way, a service can search for a vanity address by giving it a public key, and adding the key to the desired address.

You create the private key to the desired address in the same way: you connect the two keys from which the public keys have been generated. If you do this yourself after the service provider has sent you the private key he used, he never has a control over the address generated by him.

On the Vanity Address Service from Bitcoin-University.de we can generate such an address. Both standard bitcoin addresses (“1bergmann”), Segwit addresses (“3bergmann”) or native Segwit addresses (“BC1Qpergmann”) are offered. Unfortunately, a “B” is not allowed in the latter, which is why the example only works with “Hardeme”.

Currently, Bitcoin-University only offers addresses with a maximum of six tailor-made characters, soon when the new graphics cards arrive, more should also be possible.

As soon as you have entered the desired characters, Bitcoin-University would like to know a public key. Many of you will be overwhelmed from this point. Where do you get a public key from? Most of the wallets don’t spit out at all, with others the option is very hidden. I used the (desktop versioin of the) Wallet Electrum, where you can use the console with the command

Getpubkeys (‘address’)

can display the public key of a specific address. It may be that you have to unlock the console in the “View” menu first. Then I entered the key at Bitcoin-UNI. Then I should pay seven euros, which I could handle thanks to my discount codes. I also have a discount code for you, but with that you only save 25 percent: Save25Percent.

From now on the graphics cards of the Bitcoin University work and look for your desired address. As soon as they found what they found, you will get to know by email. In the email you will also find a link to the key Merging; The form on the page of the Bitcoin University is already pre-filled with the private key you have found. In order to generate the private key for the Vanity address, you have to enter the private key to the address, from which you have previously found out the public key. In Electrum you can either click on the address or in the console with the command by right click on the address or in the console

GetPrivatekeys (‘address’)

Electrum will spit out the private key with a prefix that shows the format, such as “P2PKH:”. You may not enter this part in the form of the Bitcoin University.

But wait … if we now enter the private key of our address on a form of the service provider – then it can also generate the private key for the Vanity address? We then cycled twice, just to get out in the same church, or? We have taken on a big effort to achieve the same result – the service provider knows the key? Whether he promises to extinguish him or praised him after calculating, not to save the entries in the form – that comes out of the same.

Bitcoin-University is clear. Therefore, on the one hand, they recommend opening the page using the form in private mode, for example as a private tab with the good or Chrome browser. On the other hand, you should separate the internet connection before entering the private key, and the page – preferably the entire browser – close after copying the key and checking the connection again. In this way, Bitcoin-Uin cannot save your private key at all, as everything will happen locally, in your browser.

If you want to be on the safe side, you can also install the key merging tool yourself.

In this way you can get a safe vanity address without having your computer run hot or trusting a service provider.

But what do you do with the private key? Again I can only recommend the Wallet Electrum to you. Here you can simply generate a new wallet and specify the option to use a seed or a private key.