40. The method of claim 18 , further comprising modifying the selected substring of the intermediate tokenized string of characters prior to replacing the selected substring with a token.
40. The method of claim 18 , further comprising modifying the selected substring of the intermediate tokenized string of characters prior to replacing the selected substring with a token. 41. The method of claim 40 , wherein modifying the selected substring of the intermediate tokenized string of characters comprises modifying the selected substring at least in part based on an initialization vector.