> since there are at max 999-999-9999 hashes Assuming that's meant to represent 10 digits, it's not sufficient. My phone number is one longer than that (11 di

> since there are at max 999-999-9999 hashes Assuming that's meant to represent 10 digits, it's not sufficient. My phone number is one longer than that (11 digits). If you drop the 0 prefix and use +44 instead, that'll be 12 digits (or 13 if you include the + but you could specify that as always present.) (A minor nit since it only increases the search space 10x or 100x which probably doesn't make a huge impact?)