The project has already been announced, you can go and see: https://addrstore.com
Created the topic: https://bitcointalk.org/index.php?topic=1910615.0


Of course, for pre-generated vanity addresses, the private key will already be known at least to the service that generated it, and to the user who wants to get a vanity address. But in order to safely use the pre-generated vanity address, you can use transactions with a multi-signature.


Such pre-generated vanity addresses can cost significantly less than those obtained using a partial private key. By the way, generation with the use of a partial private key is also available for us. This section is called "Personal addresses": https://addrstore.com/?category=Personal_addresses, when placing an order, the user must specify his private key.


Nothing to prove is not necessary. The private key of the pre-generated vanity address is known to us and it's a fact, there's nothing to hide and no one wants to cheat. But the user can safely use this address only using some of the capabilities of the bitcoin network (multi-transactions, P2SH addresses), or another way of using it - the user trusts our project and uses a vanity address as usual. But in any case, we delete the private key of the sold vanity address in a semi-automatic mode without the possibility of recovery.

In addition, vanity addresses can be used in P2SH-addresses (which start with 3), with a redeem script that implies the use of a multi-signature, for example 2-of-2 or 2-of-3.

Pre-generated vanity addresses can be used in transactions with a multi-signature (2-of-2), where the first address is the vanity address, the second address is the address generated by the user himself. With such a transaction, you can spend bitcoins only when you has two private keys.

The site is only a platform for demonstrating already generated vanity addresses. Only the patterns and the last 2 characters of vanity addresses are stored on the site server. Full addresses (up to 34 characters in length) and private keys to them are stored in an encrypted form in a separate repository that is not physically connected to the Internet. Only one person has access to this repository. After the sale of the vanity address and confirmation of its receipt (more details are described here: https://addrstore.com/?info=special_conditions) the private key to the address is deleted in the semi-automatic mode without the possibility of recovery.

We would like to present a unique and convenient service for getting Bitcoin vanity addresses: https://addrstore.com


What is a Bitcoin vanity address?

This is bitcoin address, which starts with a special sequence of characters, we call it a pattern. For example, the following bitcoin address 1DonationLd73pZbX3fAitt4JZv5kdrZEt has a pattern: 1Donation.


About Us:

We create vanity addresses on our own patterns and in large numbers, thanks to this:
1. the cost of the vanity addresses is much lower than for similar projects;
2. all our vanity addresses have a complexity of at least 5.15*10^13;
3. we only work with patterns of at least 8 characters in length, and all patterns are case-sensitive;
4. we are the only service that offers the generation of personal vanity addresses (generation using split-keys) with complexity up to 1.73*10^17, this is equivalent to the length of the pattern up to 10 characters.


Details:

The service offers 2 types of vanity addresses:
1. Exclusive addresses - these are the vanity addresses for which a private key is already found, which corresponds to a specific pattern. After selling an exclusive vanity address, the private key to it is reliably deleted, but if the customer does not trust our service, then exclusive addresses can be used in multisig-transactions (2-of-2 / vanity address + customer's address) or P2SH-addresses (2-of-2);
2. Personal addresses - these are the vanity addresses that are generated by our service using split-keys. How it works: the customer chooses what complexity the set of addresses he needs, then the customer generates a pair of "private key-public key", we recommend using the project https://bitaddress.org for this. When placing an order, the customer must specify the public key, the private key is kept secret. Next, our service uses customer's public key to generate vanity addresses, but private keys for these addresses can only be obtained using the private key of the customer. Thus, only the customer can be a full owner of a personal vanity address. The rationale for this approach is well described here: https://bitcointalk.org/index.php?topic=81865.msg901491#msg901491


More information here: https://addrstore.com/?info=faq


13.06.2017:
We are announcing that the AddrStore.com service now supports the P2SH vanity addresses.