摘要 |
PCT No. PCT/SE95/00955 Sec. 371 Date Mar. 14, 1997 Sec. 102(e) Date Mar. 14, 1997 PCT Filed Aug. 24, 1995 PCT Pub. No. WO96/08806 PCT Pub. Date Mar. 21, 1996A method and a device for facilitating authorized and simultaneously restraining unauthorized access to a multitude of alphanumeric sequences, for instance for credit cards, code keys and the like. According to the method every correct sequence (e.g. 5533) is encrypted by mathematically manipulating it by means of an encrypting sequence (7221) common to every correct sequence, so that every correct sequence is converted into a fictitious encrypted sequence. The credit card has a carrier (12-16) for carrying and exposing the fictitious sequence. A deciphering of the fictitious sequence is performed by a reversed mathematical manipulation of the fictitious sequence.
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