[3np]

Indeed. For anyone unfamiliar with the nature of cryptographic hashes, each character increases the difficulty to get a collision exponentially.

~10 characters are easy enough to generate on a single machine so don't rely on a vanity-prefix and the trailing couple of characters only, but getting a new .onion address matching even half of an existing one within the lifetime of civilization is unrealistic even with state-actor resources.

You'd be better off trying to brute-force Satoshi's bitcoin private keys if you're feeling that lucky...

https://github.com/cathugger/mkp224o/issues/27