Patent ID: 7448083
Filing Date: 2008-11-04
Classification: G06F,G06Q,G07F

Abstract:
1. A security system used in an apparatus which deals with secret data, comprising: a storage medium which stores the secret data; a first counting unit which counts a number of processing accesses relating to the secret data, the processing accesses including legal accesses due to requests from the apparatus and illegal accesses by an attacker or from an external apparatus other than said apparatus; a first restricting unit which restricts subsequent processing when a first count result of the first counting unit has exceeded a preset first count threshold value; a second counting unit which counts the number of times a first count result set by the first counting unit is accessed regardless of legality of each access to the first count result; and a second restricting unit which restricts subsequent processing when a second count result of the second counting unit has exceeded a preset second count threshold value which just exceeds an estimated number of possible accesses given to the first count result at requests of said apparatus.