Patent ID: 8256670

Claim:
A system for controlling access to an area using an access card, comprising: a card reader that receives a card number from the access card; a card verifier comprising: an approved list of approved card numbers; a card presented list of presented card numbers; and a processor that compares the card number to the approved list and compares the card number to the card presented list; and an access device; wherein the access device grants access to the area if the card verifier determines that the card number is on the approved list and the card number is not on the presented list; and the access device denies access to the area if the card verifier determines that the card number is not on the approved list and the card number is on the presented list; and the access device grants access to the area if the card verifier determines that the card number is not on the approved list and the card number is not on the presented list.