Numbers are too easy to crack by enumeration. You can just enumerate all possible passport numbers, encrypt them, and compare two hashes. It takes seconds on mo

Numbers are too easy to crack by enumeration. You can just enumerate all possible passport numbers, encrypt them, and compare two hashes. It takes seconds on modern CPU. Even if salt is used, all 5E6 records can be cracked in about 2 months on modern desktop, or in 1 day on 60 node cluster.