1. A method comprising: encrypting a database column of character strings using correlated and order invariant encrypting, by: converting each character in each character string into a respective numerical representation; generating a random number for each entry in the database column of character strings; mapping each numerical representation to a respective random number, wherein the mapping preserves an order of each character string in the database column relative to each of the other character strings in the database column; encrypting each random number; converting each encrypted random number into a respective numerical representation; and storing each converted encrypted random number as an encrypted database column, wherein each encrypted random number in the encrypted database column corresponds to the respective character string represented by the numerical representation mapped to the respective random number.