ILLEGAL ACCESS PROTECTION DEVICE AND IC CARD HOLDER

PROBLEM TO BE SOLVED: To provide an illegal access protection device and an IC card holder by which the card information of a non-contact IC card can be protected from illegal access to the IC card. SOLUTION: A protection sheet (illegal access protection device) 12 having a conductive winding 121 spirally wound in a plane and short-circuited between both end parts and a sheet material 122 for supporting the winding 121 is arranged oppositely to an IC card C1 and stored in a holder body. In this state, the winding 121 is magnetically coupled with the antenna part of the IC card C1 and the resonance frequency of the IC card C1 is changed, so that the IC card C1 becomes a communication disabled state. Consequently, the card information can be protected from illegal accesses to the IC card C1. Since the protection sheet 12 is provided with a switch 123 for releasing the short-circuit state between both end parts of the winding 121, the communication function of the IC card C1 can be restored by card owner's will. COPYRIGHT: (C)2005,JPO&NCIPI