Smartcard with cryptographic functionality and method and system for using such cards
First Claim
1. A method of providing cryptographic services in an organisation, the method comprising:
- providing members of the organisation with respective smartcards, each holding a secret associated with the member concerned and arranged to map an input string to a first element of an algebraic group according to a known mapping function, to multiply the first element by said secret to form a second element of said algebraic group such that there exists a computable bilinear map for the first and second elements, and to output this second element;
the members using the smartcards in the provision of at least encryption, decryption and signing cryptographic services with the same smartcard-held secret of a member being involved as required in all these services.
1 Assignment
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Accused Products
Abstract
A smartcard is provided that stores a secret associated with the user of the card. The smartcard is arranged to map an input string to a first element of an algebraic group according to a known mapping function, to multiply the first element by the stored secret to form a second element of the same algebraic group such that there exists a computable bilinear map for the first and second elements, and to output this second element. This selection of the limited functionality of the smartcard enables it to be employed in the provision of a range of cryptographic services such as encryption, decryption and signature generation. The smartcard is therefore suitable for use in an organisation where multiple cryptographic services are required.
38 Citations
30 Claims
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1. A method of providing cryptographic services in an organisation, the method comprising:
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providing members of the organisation with respective smartcards, each holding a secret associated with the member concerned and arranged to map an input string to a first element of an algebraic group according to a known mapping function, to multiply the first element by said secret to form a second element of said algebraic group such that there exists a computable bilinear map for the first and second elements, and to output this second element;
the members using the smartcards in the provision of at least encryption, decryption and signing cryptographic services with the same smartcard-held secret of a member being involved as required in all these services. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for providing cryptographically-protected processes in an organisation, the system comprising:
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a plurality of smartcards for use by corresponding members of the organisation, each smartcard comprising;
a non-volatile memory for holding a secret associated with the corresponding member, an input arrangement for receiving an input string, a first functional entity for mapping said input string to a first element of an algebraic group according to a known mapping function, a second functional entity for multiplying the first element by said secret to form a second element of said algebraic group such that there exists a computable bilinear map for the first and second elements, and an output arrangement for outputting said second element;
a plurality of process sub-systems for implementing processes that, at least when considered together, involve at least encryption, decryption and signing cryptographic services involving the use of said smartcards with the same smartcard-held secret of a member being involved as required in all these services. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A smartcard comprising:
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a non-volatile memory for holding a secret associated with a user of the card, an input arrangement for receiving an input string, a first functional entity for mapping said input string to a first element of an algebraic group according to a known mapping function, a second functional entity for multiplying the first element by said secret to form a second element of said algebraic group such that there exists a computable bilinear map for the first and second elements, and an output arrangement for outputting said second element. - View Dependent Claims (24, 25, 26)
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30. A smartcard according to claim 29, wherein said bilinear mapping function is based on a Tate or Weil pairing.
Specification