A while ago, I read some news about a huge transaction on the Bitcoin blockchain. The first few addresses used were apparently created with some kind of vanity address generator. One example is 1Lets1xxxxxx1use1xxxxxxxxxxxy2EaMkJ
.
However I recalled, when reading up on the topic a couple of years ago, that this process is very computation hungry, since it entails a brute force search for private/public keypairs. Finding a keypair with only a few predetermined public key characters would take a long time. And indeed, the Vanitygen article on the Bitcoin wiki seems to agree - finding a keypair with 12 determined public key characters would take 11,700,000 years...
So, how did they manage to generate the public key above with 27 non-random characters?
(They say that the task of finding a private key for a specific public key is futile, but extrapolating here makes you kind of wonder...)