Provided are devices, methods, systems, computer readable storage media for tokenizing data. In some examples, credit card numbers are tokenized using a pre-generated token map and absent the use of a networked database that stores a relatively large quantity of credit card numbers in a central location. The token map may be generated by a token map generator such that the token map can be used by a tokenizer to replace a portion of an account number with a token, and by a detokenizer to replace the token with the original portion of the account number. A pre-parser and parser may also be used to locate an account number and/or token in a message received over a network.