> The hashing function described above is too simple to do the job properly - dcd, hdb and various other non-words would all hash to 223 and be accepted - but it's possible to devise more complicated hashing functions so that hardly any non-words will be accepted. You may use more than one hashing function; you could derive, say, six numbers from the same word and check them all in the bit map (or in six separate bit maps), accepting the word only if all six bits were set.

Just described how a Bloom filter works.