Blooming Password – A banned password check using a bloom filter
Sorry to say this, but this is actually worse than just truncating the hash.Why? Bloom filters are designed to maintain a reasonable false positive rate while still allowing you to add items extremely quickly (high insertion rate).Since the bad password list is presumably fixed (or almost so) you can do checks faster and with a lower FP rate by just truncating the hashes and prefix sorting the list ahead of time.