Method of ratifying secret codes for memory cards
AssigneeGemplus Card International
InventorFrancois Geronimi
Life of this patent
Estimating the term…
Abstract
A method of ratifying secret codes for IC memory cards including a data processing member and a storage device for recording a secret code and data delivered to the card. It consists in determining at least one fixed-size memory zone in the storage device or systematically writing at least one bit in said zone prior to each presentation of a secret code, and in erasing all of the bits recorded in the fixed-size zone once the data processor member observes that the presented secret code corresponds to the secret code recorded in the card.
Claims8
A method of ratifying secret codes for IC memory cards which cards include a data processing member, and a storage device for recording a secret code and data delivered to the card, wherein the method comprises writing in at least one fixed-size memory zone in the storage device at least one bit in said zone prior to each presentation of a secret code, and in erasing all of the bits recorded in the fixed-size zone once the data processor member detects that the presented secret code corresponds to the secret code recorded in the card.
A device for ratifying secret codes comprising an IC memory card including a data processing member and a storage device for recording a secret code and data delivered to the card, at least one fixed-size memory data zone means in the storage device for systematically writing at least one bit in said memory zone means prior to each presentation of a secret code, and means for erasing all of th bits recorded in the fixed-size memory zone means once the data processor member observes that the presented code corresonds to the secret code recorded in the card.
A security circuit for a memory card comprising
- a fixed memory in said card containing a secret code;
- an erasable memory in said card for storing a predetermined number of bits from 0 to n bits;
- means for adding a bit to said erasable memory before a secret code is entered by a user of the card;
- and
- means for comparing said user entered secret code with said secret code in said fixed memory and for resetting said erasable memory when said codes agree.
A security circuit for a memory card comprising
- (a) a fixed memory in said card containing a secret code;
- (b) an erasable memory in said card for storing a predetermined number of bits;
- (c) means for applying a bit to said erasable memory before a secret code is entered by a user of the card;
- (d) means for determining if said erasable memory for the storage of bits has less than or is at the predetermined number, and for generating a pass signal if less than the predetermined number and for generating a prevent signal if at the predetermined number;
- and
- (e) means activated by said pass signal for comparing said user entered secret code with said secret code in fixed memory and for generating a first signal when said codes agree, and for generating a second signal when said codes do not agree;
- (f) means responsive to said prevent signal or to said second signal to prevent further use of the card;
- and
- (g) means responsive to said first signal for resetting the erasable memory to the beginning of said predetermined number of bits, and for permitting further use of the card.
Dependencies are inferred from the claim text.