Patent ID: 7302572
Filing Date: 2007-11-27
Classification: G06F,G06Q,G07F,H04L

Abstract:
1. An authentication method for authenticating a portable information recording medium ( 100 ) as valid when external equipment ( 200 ) accesses said portable information recording medium, comprising: an operation defining step for determining a first key (α), a second key (β), an encoding operation, and a decoding operation so that encoded data (C) is obtained by executing said encoding operation using said first key (α) for arbitrary authentication data (R) and data identical to said authentication data (R) is obtained by executing said decoding operation using said second key (β); a medium preparing step in which said first key (α) is stored in the portable information recording medium ( a random number transmitting step (S an authentication data storing step (S a judging step (S an encoding step (S a decoding step (S an authenticating step (S