There's already a service for this: bitcoinvanitygen.com
This means that you'll really need more trust and also lower price than the existing service.
The service has
NO trust at all, in fact, it's been often discussed (and IIRC even proven) that the service is indeed
nothing but scam.
I don't know why people bring them up again and again (I've often warned others about that site after the next guy 'suggested' using them...)
Using any 3rd party for creating a wallet is a security risk people already know and not many are willing to take.
While you can run a program (publicly available) to generate vanity address, most will do that in the privacy of their own computer.
With split-key creation, this risk can be minimized, making it (practically) safe to use addresses generated that way (by a 3rd party, however not fully).
While you can run a program (publicly available) to generate vanity address, most will do that in the privacy of their own computer.
Those that got the hardware necessary, but in some cases, with long prefixes, issuing this job to another person can be the better option for you.