Process and system for transmission of signed messages

• US 4,467,139 A
• Filed: 03/12/1981
• Issued: 08/21/1984
• Est. Priority Date: 04/09/1980
• Status: Expired due to Term

• Current Assignee: Compagnie Internationale Pour L'Informatique Cii-Honeywell Bull
• Original Assignee: Compagnie Internationale Pour L'Informatique Cii-Honeywell Bull
• Inventors: Mollier, Jean H.
• Primary Examiner(s): Cangialosi, Sal
• Application Number:
  US06/242,850
• Time in Patent Office: 1,258 Days
• Field of Search: 178/22.05, 178/22.08, 178/22.13, 178/22.16
• US Class Current: 713/181
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

The transmission of signed messages occurs between a transmitter (1) and a receiver (3) connected by a transmission line system (2). The transmitter (1) and the receiver (3) respectively comprise a coding device 7 and a decoding device 11. Means 4 situated at the transmitter supply a signature SG as a function of the message M which is to be transmitted. The message associated with its signature, as well as a common key E, are transmitted by the transmitter towards the receiver after coding by means of an intrinsic key R₁. Upon being received, the message M linked with its signature SG is decoded by means of an intrinsic key R₂ determined at the receiver location in such manner as to establish equality between intrinsic keys R₁ and R₂.

Claims

1. A process for the transmission of signed messages M between a transmitter and a receiver connected via a transmission line system, the transmitter including a coding device and the receiver including a decoding device, said process comprising:

calculating a signature SG at the transmitter location as a function of the message M which is to be transmitted and as a function of a secret code J which enables the subsequent certification of the signature;

linking the message with the signature thus obtained;

generating at the transmitter location a common key E;

calculating at the transmitter location as a function of at least the common key E an intrinsic coding key R₁ and employing the intrinsic coding key R₁ to encode the linked message and signature;

causing the transmitter to transmit the common key E and the encoded message and signature; and

calculating at the receiver location as a function of at least the common key E an intrinsic decoding key R₂ and employing the intrinsic decoding key R₂ to decode the coded message and signature.

2. A process for the transmission of signed messages according to claim 1, wherein the intrinsic coding and decoding keys calculated at the transmitter and receiver locations are the same.

3. A process for the transmission of signed messages according to claim 1, wherein each intrinsic coding key is calculated also as a function of a secret code S which must match at the transmitter and receiver locations, and wherein the secret code S differs from the secret code J.

4. A process for the transmission of signed messages according to claim 2, wherein each intrinsic key is calculated also as a function of a secret code S which must match at the transmitter and receiver locations, and wherein the secret code S differs from the secret code J.

5. A process for the transmission of signed messages according to claim 1, wherein the common key E transmitted by the transmitter to the receiver is a random number.

6. A process for the transmission of signed messages according to claim 2, wherein the common key E transmitted by the transmitter to the receiver is a random number.

7. A process for the transmission of signed messages according to claim 3, wherein the common key E transmitted by the transmitter to the receiver is a random number.

8. A process for the transmission of signed messages according to claim 4, wherein the common key E transmitted by the transmitter to the receiver is a random number.

9. A process for the transmission of signed messages according to claim 1, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

10. A process for the transmission of signed messages according to claim 2, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

11. A process for the transmission of signed messages according to claim 3, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

12. A process for the transmission of signed messages according to claim 4, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

13. A process for the transmission of signed messages according to claim 5, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

14. A process for the transmission of signed messages according to claim 6, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

15. A process for the transmission of signed messages according to claim 7, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

16. A process for the transmission of signed messages according to claim 8, wherein the signature is calculated also as a function of an identification code I_n linked to the message M to be transmitted, and which further comprises causing the transmitter to transmit the identification code I_n.

17. A process for the transmission of signed messages according to claim 1, wherein the the message and signature are linked by concatenation.

18. A process for the transmission of signed messages according to claim 2, wherein the the message and signature are linked by concatenation.

19. A process for the transmission of signed messages according to claim 3, wherein the the message and signature are linked by concatenation.

20. A process for the transmission of signed messages according to claim 4, wherein the the message and signature are linked by concatenation.

21. A process for the transmission of signed messages according to claim 5, wherein the the message and signature are linked by concatenation.

22. A process for the transmission of signed messages according to claim 6, wherein the the message and signature are linked by concatenation.

23. A process for the transmission of signed messages according to claim 7, wherein the the message and signature are linked by concatenation.

24. A process for the transmission of signed messages according to claim 8, wherein the the message and signature are linked by concatenation.

25. A process for the transmission of signed messages according to claim 9, wherein the the message and signature are linked by concatenation.

26. A process for the transmission of signed messages according to claim 10, wherein the the message and signature are linked by concatenation.

27. A process for the transmission of signed messages according to claim 11, wherein the the message and signature are linked by concatenation.

28. A process for the transmission of signed messages according to claim 12, wherein the the message and signature are linked by concatenation.

29. A process for the transmission of signed messages according to claim 13, wherein the the message and signature are linked by concatenation.

30. A process for the transmission of signed messages according to claim 14, wherein the the message and signature are linked by concatenation.

31. A process for the transmission of signed messages according to claim 15, wherein the the message and signature are linked by concatenation.

32. A process for the transmission of signed messages according to claim 16, wherein the the message and signature are linked by concatenation.

33. A system for the transmission of signed messages M between a transmitter and a receiver interconnected by a transmission line system, the transmitter and receiver respectively including a coder and a decoder for coding and decoding each message M and its signature, said system comprising:

means located at the transmitter for calculating a signature SG as a function of the message M which is to be transmitted and as a function of a secret code J which enables the subsequent certification of the signature;

means located at the transmitter for linking the message M which is to be transmitted with the calculated signature;

means located at the transmitter for generating a common key E;

means located at the transmitter for calculating an intrinsic coding key R₁ as a function of at least the common key E for use by the coder to encode the linked message M and signature SG;

means in the transmitter for transmitting the common key E and the encoded message and signature to the receiver; and

means located at the receiver for calculating an intrinsic decoding key R₂ as a function of at least the common key E for use by the decoder to decode the encoded message M linked with its signature SG.

34. A system for the transmission of signed messages between a transmitter and a receiver according to claim 33, wherein said means for calculating an intrinsic coding key R₁ and said means for calculating an intrinsic decoding key R₂ each comprise a portable electronic object including;

a storage device containing a secret code S which must match at the transmitter and receiver and a program P₁ ;

coupling means for connecting each of said portable objects to the respective one of the transmitter and receiver for transmitting the common key E from the respective one of the transmitter or receiver to said portable object and for transmitting the respective intrinsic key R₁ or R₂ from the portable object to the respective one of the transmitter and receiver; and

processing means situated between the coupling means and the said storage device for calculating the respective intrinsic key R₁ or R₂ by execution of the program P₁ as a function of the values of the secret code S and of the common key E.

35. A system for the transmission of signed messages between a transmitter and a receiver according to claim 33, wherein said means in the transmitter for generating a common key E comprises a random number generator.

36. A system for the transmission of signed messages between a transmitter and a receiver according to claim 34, wherein said means in the transmitter for generating a common key E comprises a random number generator.

37. A system for the transmission of signed messages between a transmitter and a receiver according to claim 33, wherein said means for calculating a signature SG comprises a portable electronic object including:

a storage device containing the secret code J which enables the subsequent certification of the signature and a program P₂ ;

coupling means for connecting said portable object to the transmitter for transmitting the message M from said transmitter to said portable object and for transmitting the signature SG from the portable object to the transmitter; and

processing means situated between said coupling means and said storage device for calculating the signature SG as a function of the program P₂, of the secret code J, and of the message M.

38. A system for the transmission of signed messages between a transmitter and a receiver according to claim 34, wherein said means for calculating a signature SG also comprises said portable electronic object, and wherein:

said storage device also contains the secret code J which enables the subsequent certification of the signature, the secret code J differing from the secret code S, and a program P₂ ;

said coupling means for connecting said portable object to the transmitter is also for transmitting the message M from said transmitter to said portable object and for transmitting the signature SG from the portable object to the transmitter; and

said processing means situated between said coupling means and said storage device is also for calculating the signature SG as a function of the program P₂, of the secret code J, and of the message M.

39. A system for the transmission of signed messages between a transmitter and a receiver according to claim 35, wherein said means for calculating a signature SG comprises a portable electronic object including:

a storage device containing the secret code J which enables the subsequent certification of the signature and a program P₂ ;

coupling means for connecting said portable object to the transmitter for transmitting the message M from said transmitter to said portable object and for transmitting the signature SG from the portable object to the transmitter; and

processing means situated between said coupling means and said storage device for calculating the signature SG as a function of the program P₂, of the secret code J, and of the message M.

40. A system for the transmission of signed messages between a transmitter and a receiver according to claim 36, wherein said means for calculating a signature SG also comprises said portable electronic object, and wherein:

said storage device also contains the secret code J which enables the subsequent certification of the signature, the secret code J differing from the secret code S, and a program P₂ ;

said coupling means for connecting said portable object to the transmitter is also for transmitting the message M from said transmitter to said portable object and for transmitting the signature SG from the portable object to the transmitter; and

said processing means situated between said coupling means and said storage device is also for calculating the signature SG as a function of the program P₂, of the secret code J, and of the message M.

41. A system for the transmission of signed messages between a transmitter and a receiver according to claim 33, wherein said means for linking the message which is to be transmitted with the calculated signature comprises a register for concatenating the message M and the signature.

42. A system for the transmission of signed messages between a transmitter and a receiver according to claim 37, wherein said means for linking the message which is to be transmitted with the calculated signature comprises a register for concatenating the message M and the signature.

43. A system for the transmission of signed messages between a transmitter and a receiver according to claim 38, wherein said means for linking the message which is to be transmitted with the calculated signature comprises a register for concatenating the message M and the signature.

44. A system for the transmission of signed messages between a transmitter and a receiver according to claim 37, wherein the secret codes J and S are inaccessible to agencies external to the system.

45. A system for the transmission of signed messages in accordance with claim 34, wherein:

said storage device included in said portable electronic object also contains a table of message indentification codes I_n corresponding to messages which are authorized to be transmitted or received, these identification codes being stored as table entries at predetermined addresses;

wherein

said transmitter includes an address generator for determining from an identification code I_n linked to the message M the address within said storage device at which the corresponding identification code I_n is stored;

wherein

said coupling means also transmits the address to the portable object; and

wherein

said processing means calculates the intrinsic key as a function also of the identification code I_n read from the storage device at the transmitted address.

46. A system for the transmission of signed messages in accordance with claim 37, wherein:

said storage device included in said portable electronic object also contains a table of message identification codes I_n corresponding to messages which are authorized to be transmitted or received, these identification codes being stored as table entries at predetermined addresses;

wherein

said transmitter includes an address generator for determining from an indentification code I_n linked to the message M the address within said storage device at which the corresponding identification code I_n is stored;

wherein

said coupling means also transmits the address to the portable object; and

wherein

said processing means calculates the signature SG as a function also of the identification code I_n read from the storage device at the transmitted address.

47. A system for the transmission of signed messages in accordance with claim 38, wherein:

said storage device included in said portable electronic object also contains a table of message identification codes I_n corresponding to messages which are authorized to be transmitted or received, these identification codes being stored as table entries at predetermined addresses;

wherein

said transmitter includes an address generator for determining from an indentification code I_n linked to the message M the address within said storage device at which the corresponding identification code I_n is stored;

wherein

said coupling means also transmit the address to the portable object; and

wherein

said processing means calculates the intrinsic key as a function also of the identification code I_n read from the storage device at the transmitted address and calculates the signature SG as a function also of the identification code I_n read from the storage device at the transmitted address.

48. A system for the transmission of signed messages in accordance with claim 39, wherein:

said storage device included in said portable electronic object also contains a table of message identification codes I_n corresponding to messages which are authorized to be transmitted or received, these identification codes being stored as table entries at predetermined addresses;

wherein

said transmitter includes an address generator for determining from an identification code I_n linked to the message M the address within said storage device at which the corresponding identification code I_n is stored;

wherein

said coupling means also transmits the address to the portable object; and

wherein

said processing means calculates the signature SG as a function also of the identification code I_n read from the storage device at the transmitted address.

49. A system for the transmission of signed messages in accordance with claim 40, wherein;

said storage device included in said portable electronic object also contains a table of message identification codes I_n corresponding to messages which are authorized to be transmitted or received, these identification codes being stored as table entries at predetermined addresses;

wherein

said transmitter includes an address generator for determining from an identification code I_n linked to the message M the address within said storage device at which the corresponding identification code I_n is stored;

wherein

said coupling means also transmits the address to the portable object; and

wherein

said processing means calculates the intrinsic key as a function also of the identification code I_n read from the storage device at the transmitted address and calculates the signature SG as a function also of the identification code I_n read from the storage device at the transmitted address.