Method and device for protecting a reading device for card-shaped data carriers from unauthorized evaluation or copying of magnetically encoded data of an inserted card-shaped data carrier

Abstract

The invention relates to a method and devices for protecting a reading device (1) for card-shaped data carriers (2) from the unauthorized evaluation or copying of magnetically encoded data which are acquired on the reading device (1) for card-shaped data carriers (2). According to said method, a magnetic noise field (18) is produced by means of a noise field coil (17). The at least one noise filed coil (17) is implemented or arranged in such a manner that the authorized magnetic field read head (10) is also influenced by the noise field (18) of the noise field coil (17) when the magnetically encoded data of a card-shaped data carrier (2) are read. An output signal or sum signal of the authorized magnetic field read head (10) produced from the useful signal of a card-shaped data carrier (2) and the influences of the noise field (18) is acquired. The influence of the noise field (18) of the noise field coil (17) in the output signal or sum signal of the authorized magnetic field read head (10) is compensated or filtered out and the useful signal is selectively filtered out from the output signal or sum signal of the authorized magnetic field read head (10).

Description

technical field [0001] The invention relates to a method and a device for preventing unauthorized and undetected analysis or copying of information stored on a card-shaped magnetic data carrier, as set forth in claims 1, 14, 24 and 26. Background technique [0002] In particular when used in conjunction with debit cards, it has repeatedly occurred that automated teller machines or similar service machines equipped with corresponding reading devices for such debit cards are used by unauthorized third parties with the intention of defrauding The manipulation is carried out so that when a credulous user uses such an automatic device as intended, the data recorded on the magnetic tracks of the card-like data carrier are stolen without detection and with criminal intent. For this purpose, for example, an additional read head is unobtrusively mounted in front of the card insertion opening, which invisibly captures the data stored on the card when it is inserted. These data are st...

AI Technical Summary

Problems solved by technology

However, this measure can only be used with a limited selection of magnetic card readers with sufficiently deep construction types, in particular magnetic card readers in which the card completely disappears in the reading opening before the card's magnetic stripe reaches the internal or legitimate reading head. Only possible in the output

First of all, in the magnetic card reader of the short structure type favored by the access control system, the internal legal reading head is arranged relatively close to the card reading port, and this remedy is impossible.

Especially in the case of plug-in readers or swipe readers (Durchzugsleser), this expedient generally fails completely

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