Wired microcircuit card and a method for transactions between a corresponding wired microcircuit card and a terminal
First Claim
1. A microcircuit card, comprising:
- communication interface means (7);
first internal memory means (11) having an output (20);
second (40) internal memory means;
wired circuit means (30) capable of using the contents of said second internal memory means (40) for establishing a first serial cryptographic function of two operands; and
logic control means responsive to interrogation of predetermined addresses of said first internal memory means (11) accompanied by a keyword (19) for applying said keyword (19) and the output (20) of the first internal memory means as operands of the wired circuit means (30), respectively, and for applying an output of the wired circuit means (30) to said communication interface means (7).
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Accused Products
Abstract
The invention concerns a microcircuit card of the kind comprising:
a communication interface;
an internal memoryp
a wired processor unit allowing this internal memory to be addressed from the outside.
According to the main characteristic of the invention, provision is made for a secret internal memory zone not addressable from the outside, and the processor unit comprises a wired circuit capable of using the contents of the secret memory for establishing a first serial cryptographic function of two operands and means reacting to the interrogation of predetermined addresses of the internal memory, accompanied by a keyword by applying this keyword and the output of the internal memory as operands of the wired circuit, whilst the output of the wired circuit is applied to the interface.
56 Citations
28 Claims
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1. A microcircuit card, comprising:
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communication interface means (7); first internal memory means (11) having an output (20); second (40) internal memory means; wired circuit means (30) capable of using the contents of said second internal memory means (40) for establishing a first serial cryptographic function of two operands; and logic control means responsive to interrogation of predetermined addresses of said first internal memory means (11) accompanied by a keyword (19) for applying said keyword (19) and the output (20) of the first internal memory means as operands of the wired circuit means (30), respectively, and for applying an output of the wired circuit means (30) to said communication interface means (7). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 25, 26, 27, 28)
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14. In a method for transactions between at least one terminal and at least one wired microcircuit card capable of cooperating with this terminal, the improvement comprising the following steps:
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a) providing the card; with communication interface means, with internal memory means, with a wired processor unit allowing said internal memory means to be externally addressed; b) making provision in the card for an internal memory zone not externally addressable; c) prestoring in the card; identification bits of the card value bits to which there is allocated a unit value that can be used up by writing thereon; and signature bits of the card; d) providing the processor unit of the card with a wired circuit capable of using the contents of the internal memory zone for establishing a first serial cryptographic function of the two operands; e) during a validation request for a transaction assumed to be coming from the card, e1) receiving at the terminal the output of said internal memory means; e2) providing the terminal with means capable of generating a keyword; e3) transmitting the keyword from the terminal; e4) calculating at the card the transform of the keyword and of the output of said internal memory means by the first cryptographic function; e5) receiving from the card said transform by the first cryptographic function; e6) calculating at the terminal the transform of the keyword and of the output of said internal memory means by the first cryptographic function; and e7) deciding the validation according to the comparison of the transform received from the card and the transform calculated by the terminal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification