43. An apparatus for tokenization of sensitive strings, the apparatus comprising: a first data processing system, the first data processing system comprising: an input configured to: receive a sensitive string of characters; and a processor configured to: select a substring of the sensitive string of characters; replace the selected substring of the sensitive string of characters with a first token from a set of tokens to form an intermediate tokenized string of characters; select a substring of the intermediate tokenized string of characters, the selected substring of the intermediate tokenized string of characters including at least one character replaced by the first token; and replace the selected substring of the intermediate tokenized string of characters with a second token different from the first token from the set of tokens to form a final tokenized string of characters.
43. An apparatus for tokenization of sensitive strings, the apparatus comprising: a first data processing system, the first data processing system comprising: an input configured to: receive a sensitive string of characters; and a processor configured to: select a substring of the sensitive string of characters; replace the selected substring of the sensitive string of characters with a first token from a set of tokens to form an intermediate tokenized string of characters; select a substring of the intermediate tokenized string of characters, the selected substring of the intermediate tokenized string of characters including at least one character replaced by the first token; and replace the selected substring of the intermediate tokenized string of characters with a second token different from the first token from the set of tokens to form a final tokenized string of characters. 47. The apparatus of claim 43 , wherein the first data processing system is a local processing system.