PIN Verification With Multiple Personal Authentication Codes
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
This article describes a compartmentalized transaction security facility which is an improvement or refinement on the method described in [*]. The improvement provides a defense against a "substituted ID" attack by calculating the user's personal authentication code (PAC) as a function of the user's identifier (ID) and authentication parameter (AP) rather than AP alone. Fig. 1 illustrates the calculation of PAC2, where ID, PIN, KPAC and KA2 are the same as defined in [*]. Fig. 2 illustrates the calculation of PAC1, where ID, PIN, KPAC and KA1 are the same as defined in [*] and PAC2 is the same as defined in Fig. 1 of this article. Similar modifications could be made to the calculations of PAC4, PAC5 and PAC6 in [*], although this is not shown. Fig.