METHOD FOR TOKENIZING A BANK CARD NUMBER AND METHOD FOR DETOKENIZING A BANK CARD NUMBER

摘要

The claimed method for tokenizing a bank card number comprises the steps of: obtaining a PAN and breaking it down into the following component parts: a bank identification number (BIN) consisting of the first six symbols, a mask (MASK) consisting of the last four symbols, and a middle part (mPAN); determining a shift value in a substitution table, which entails: calculating a first shift value with respect to the substitution table by cryptographically transforming a concatenated line of the values BIN and MASK; calculating a second shift value with respect to the substitution table by cryptographically transforming mPAN; and calculating a total shift value by adding together said first and second shift values; calculating an index in the substitution table by normalizing the total shift value with respect to the substitution table, wherein normalization is performed on the basis of the dimensionality of the table as the remainder of the division of the shift by the number of lines in the table, resulting in the desired index in the substitution table; using said index to select from the substitution table a tokenized part zPAN of the number to substitute for mPAN; and generating a tokenized card number DPAN by substituting mPAN with zPAN and using the BIN and MASK of the obtained PAN number.