Method for processing transaction using variable pan

PURPOSE: A transaction processing method using a dynamic primary account number (PAN) is provided to improve security when a person makes a payment by credit card, to minimize the exposure of financial information, and to maximally use a former payment system. CONSTITUTION: A dynamic PAN area is dynamically encoded by designating an application transaction count (ATC) and a random number generated by a payment device every time payment is performed as a variable. [Reference numerals] (100) Hash function; (20) Card reader slot; (AA) Sales statement; (BB,DD,GG,II) First area; (CC,EE,HH,JJ) Second area; (FF,NN) Approval result; (KK) Approval request; (LL) Check information about a credit card; (MM) D-PAN → PAN inducement; (OO) Collect and add up sales statements; (PP) Collect and add up sales statements; (QQ) Check a limit and judge validity; (RR) Judge a credit card company by using BIN