A computer-readable medium storing computer program instructions, which, when executed by a processor, cause the processor to perform a method of tokenization, the method comprising the steps of receiving a request for tokenization from a user, the request including a Session Token; decoding and validating the Session Token; retrieving a token definition, a token key, and a security policy; appending the user key and the token key to the received value to create an input value; replacing each input value character with a known character to create a replacement input value using a lookup table; generating a secure hash of the replacement input value to create a derived key; substituting characters of the replacement input value with a character from lookup tables to create a third input value; and returning the input value to the user.