Magnet information cards
OwnerLee M. Cheng, Lee L. Cheng +1inventors
InventorsLee M. Cheng, Lee L. Cheng, Man C. Chu
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Abstract
Magnetic cards are provided with unique card signatures which include a number of bits, some of which have intermediate magnetic levels. As a result a card reader allocates randomly either a one or a zero to the intermediate level bits. The random allocation provides a test for the genuineness of the card. The intermediate level bits are formed as a result of inherent inconsistencies in the characteristic of a normal magnetic stripe along its length. It is not possible therefore to readily, if at all, reproduce patterns of intermediate level bits in a duplicate because the stripe on the duplicate will have differently arranged inconsistencies along its length.
Claims10
A magnetic card having normal coded information carried on the card, each bit of the normal coded information being formed by a magnetic value representing either a one or a zero for detection by a card reader arranged to normally allocate either a one or a zero to each bit, including a card signature formed by bits positioned at fixed relative positions on the card having intermediate magnetic values to which in use the reader randomly allocates a one or a zero.
Dependencies are inferred from the claim text.