1. A computer-implemented method for generating a bigram database, the method comprising: receiving a plurality of domain names; tokenizing, by a processor, the plurality of domain names; generating, by the processor, a plurality of token bigrams from the tokenized domain names; filtering, by the processor, the plurality of token bigrams; ranking, by the processor, the plurality of token bigrams; and storing, in a memory, the filtered and ranked token bigrams in a bigram database.