| 摘要 |
<p>Disclosed are a method and device using ultrasound for determining a card swipe by a mobile phone within a safe distance configured, comprising: a card reader device (2) transmitting ultrasound information, the mobile terminal or a multi-interface integrated circuit card receiving the ultrasound information, and confirming an identity by means of the ultrasound information or radio information, when the identity is confirmed, calculating a time difference between the time when a ultrasound signal is received and the time when the radio information is transmitted, and converting the time difference into the distance between the mobile terminal or the multi-interface integrated circuit card and the reader device (2); and comparing to the safe distance configured the distance acquired via calculation between the mobile terminal or the multi-interface integrated circuit card and the card reader device (2), if the distance between the two is less than the safe distance configured, then permitting the card swipe. The method prevents the susceptibility to defraudation and attack when utilizing the principle that electromagnetic field intensity changes with distance to measure the distance, thus ensuring that the card swipe is only allowed within the range of the safe distance, while at the same time ensuring the convenience for the card swipe.</p> |
