US5748782A
Expired / Lapsed
US
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Device for implementing a message signature system and chip card comprising such a device
Assignee: De la Rue Cartes et Systemes SAS
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Filing: 1995-03-28
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Granted: 1998-05-05
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Expires: 2015-03-28
Abstract
Abstract This provides a first device for implementing an RSA-type protected data exchange system for the signing of messages and the verification of the signed messages, and a second device for inhibiting the encryption anti decryption functions inherent of such systems so as to authorize only the signature and signature functions and public key authentication.
Inventors
- 👤 Ronald Ferreira
- 👤 Joseph Hoppe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:16
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/10; G07F7/1016; H; H04; H04L; H04L9/00; H04L9/30; H04L9/3006; H04L9/302; H04L9/32; H04L9/3247; H04L9/3249
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
80 words
A device for implementing message signature functions and signature authentication functions for signed messages in an RSA-type protected data exchange system, comprising: an input source that receives an input; means for inhibiting using the message signature and the signature authentication functions for application to the input; and means for comparing each message to be signed with a predetermined structure required for all coherent messages and for inhibiting the signature of a message which does not comply with said predetermined structure.
Claim 2
Independent Claim
80 words
A device for implementing message signature functions and signature authentication functions for signed messages in an RSA-type protected data exchange system, comprising: an input source that receives an input; means for inhibiting using the message signature and the signature authentication functions for application to the input; and means for comparing each message to be signed with a predetermined structure required for all coherent messages and for inhibiting the signature of a message which does not comply with said predetermined structure.
Claim 3
Dependent Claim
52 words
A device as claimed in claim 2, characterized in that it comprises means for comparing, after authentication of a signature of a signed message (Ms), the message obtained (Mo') with said predetermined structure, and means for preventing the output of the message obtained when it does not comply with said predetermined structure.
Claim 4
Dependent Claim
43 words
A device as claimed in claim 1, characterized in that it comprises means for applying a condensation function (H) to all messages (Mo) before signing, and for subsequently outputting the condensed and signed message (Ms), and also the "plain" message (Mo), if necessary.
Claim 5
Dependent Claim
64 words
A device as claimed in claim 3, characterized in that it comprises means for comparing, after authentication of a signature of a condensed and signed message (Ms), the condensed message obtained (X) with the "plain" message emitted (Mo) whereto said condensation function (H) has been applied first, and means for preventing the output of the "plain" message when the means for comparing finds non-correspondence.
Claim 6
Dependent Claim
44 words
A device as claimed in claim 4, characterized in that said means are used to implement the public key certificate (C A ) concept and public parameters (PP A ) in order to authenticate the public keys received (e A , n A ).
Claim 7
Dependent Claim
36 words
A device as claimed in claim 1, characterized in that a criterion for use is associated with each secret key in order to enable the authorization of the decryption function for a restricted number of users.
Claim 8
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 1.
Claim 9
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 1.
Claim 10
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 2.
Claim 11
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 3.
Claim 12
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 4.
Claim 13
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 5.
Claim 14
Dependent Claim
22 words
A chip card, utilizing an RSA-type protected data exchange system, characterized in that it comprises a device as claimed in claim 6.
Claim 15
Independent Claim
77 words
A method for implementing, in conformity with an RSA-type protected data exchange, a message signature function, comprising the steps of: receiving a message to be signed; comparing the message to be signed with a predetermined structure which is required for all coherent messages; and preventing signature of the message to be signed if the message does not have the predetermined structure thereby preventing the use of the message signature function to decrypt the message to be signed.
Claim 16
Independent Claim
77 words
A method for implementing, in conformity with an RSA-type protected data exchange, a message signature function, comprising the steps of: receiving a message to be signed; comparing the message to be signed with a predetermined structure which is required for all coherent messages; and preventing signature of the message to be signed if the message does not have the predetermined structure thereby preventing the use of the message signature function to decrypt the message to be signed.
Claim 17
Independent Claim
78 words
A method for implementing, in conformity with an RSA-type protected data exchange, a signature authentication function for signed messages, comprising the steps of: receiving a signed message; authenticating the signed message; comparing the authenticated signed message with a predetermined structure which is required for all coherent messages; and preventing the output of the authenticated signed message when it does not have the predetermined structure thereby preventing the use of the signature authentication function to encrypt the signed message.
Claim 18
Independent Claim
78 words
A method for implementing, in conformity with an RSA-type protected data exchange, a signature authentication function for signed messages, comprising the steps of: receiving a signed message; authenticating the signed message; comparing the authenticated signed message with a predetermined structure which is required for all coherent messages; and preventing the output of the authenticated signed message when it does not have the predetermined structure thereby preventing the use of the signature authentication function to encrypt the signed message.
Claim 19
Independent Claim
63 words
A method for implementing message signature functions in an RSA-type protected data exchange system, comprising: receiving a message to be signed; applying a condensation function to the message to be signed to create a condensed message; conforming the condensed message to a predefined pattern thereby preventing the use of the message signature function; signing the condensed message; and outputting the signed condensed message.
Claim 20
Independent Claim
63 words
A method for implementing message signature functions in an RSA-type protected data exchange system, comprising: receiving a message to be signed; applying a condensation function to the message to be signed to create a condensed message; conforming the condensed message to a predefined pattern thereby preventing the use of the message signature function; signing the condensed message; and outputting the signed condensed message.
Claim 21
Dependent Claim
18 words
The method in accordance with claim 16, further including the step of outputting the message to be signed.
Claim 22
Dependent Claim
66 words
The method in accordance with claim 17, wherein a signature authentication is performed on the signed condensed message by performing the further steps of: authenticating the signed condensed message; comparing the authenticated signed message with the message to be signed whereto said condensation function has been first applied; and preventing the output of the message to be signed if the step of comparing results in non-correspondence.
Claim 23
Independent Claim
84 words
A device for implementing, in conformity with an RSA-type protected data exchange, a message signature function, comprising: means for receiving a message to be signed; comparison means for comparing the message to be signed with a predetermined structure which is required for all coherent messages; and means for preventing signature of the message to be signed if the message to be signed does not have the predetermined structure, thereby preventing the use of the message signature function to decrypt the message to be signed.
Claim 24
Independent Claim
84 words
A device for implementing, in conformity with an RSA-type protected data exchange, a message signature function, comprising: means for receiving a message to be signed; comparison means for comparing the message to be signed with a predetermined structure which is required for all coherent messages; and means for preventing signature of the message to be signed if the message to be signed does not have the predetermined structure, thereby preventing the use of the message signature function to decrypt the message to be signed.
Claim 25
Independent Claim
83 words
A device for implementing, in conformity with an RSA-type protected data exchange, a signature authentication function for signed messages, comprising: means for receiving a signed message; means for authenticating the signed message; means for comparing the authenticated signed message with a predetermined structure which is required for all coherent messages; and means for preventing the output of the authenticated signed message when it does not have the predetermined structure, thereby preventing the use of the signature authentication function to encrypt the signed message.
Claim 26
Independent Claim
83 words
A device for implementing, in conformity with an RSA-type protected data exchange, a signature authentication function for signed messages, comprising: means for receiving a signed message; means for authenticating the signed message; means for comparing the authenticated signed message with a predetermined structure which is required for all coherent messages; and means for preventing the output of the authenticated signed message when it does not have the predetermined structure, thereby preventing the use of the signature authentication function to encrypt the signed message.
Claim 27
Independent Claim
89 words
A device for implementing message signature functions and signature authentication functions for signed messages in an RSA-type protected data exchange system, comprising: an input source that receives an input; means for inhibiting using the message signature and the signature authentication functions for application to the input; and means for comparing a signed message obtained after authentication of a signature with a predetermined structure required for all coherent messages; and means for preventing an output of the signed message when the signed message does not comply with the predetermined structure.
Claim 28
Independent Claim
89 words
A device for implementing message signature functions and signature authentication functions for signed messages in an RSA-type protected data exchange system, comprising: an input source that receives an input; means for inhibiting using the message signature and the signature authentication functions for application to the input; and means for comparing a signed message obtained after authentication of a signature with a predetermined structure required for all coherent messages; and means for preventing an output of the signed message when the signed message does not comply with the predetermined structure.
Claim 29
Dependent Claim
35 words
The device of claim 21, further comprising means for comparing each message to be signed with the predetermined structure and for inhibiting the signature of each message which does not comply with the predetermined structure.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |