Resilient cryptographic scheme

• US RE44,670 E1
• Filed: 09/13/2012
• Issued: 12/24/2013
• Est. Priority Date: 01/20/1999
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Certicom Corporation (Blackberry Limited)
• Inventors: Johnson, Donald B., Vanstone, Scott A.
• Primary Examiner(s): REVAK, CHRISTOPHER A
• Application Number:
  US13/615,389
• Time in Patent Office: 467 Days
• Field of Search: None
• US Class Current: 713/176
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3249 using RSA or related signature schemes, e.g. Rabin scheme

Abstract

A method for communicating information between at least a pair of correspondents, the method comprising the steps of each of the correspondents selecting a plurality of cryptographic algorithms known to each of the correspondents. One of the correspondents applies the algorithms in a predetermined manner to a message for producing a set of processed information. The set of processed information is transmitted to the other correspondent. The other correspondent applies complimentary operations of the cryptographic schemes in accordance with the predetermined manner for deriving information related to the message from the processed information.

Claims

1. A method for communicating information, in a data communication system, between at least a first correspondent and a second correspondent interconnected through a data communication channel therebetween, said method comprising the steps of:

a) selecting a plurality of cryptographic algorithms known to said first correspondent and second correspondent;

b) said first correspondent applying each of said selected cryptographic algorithms to the same information in a common message in a predetermined manner for producing for that algorithm a corresponding set of processed information;

c) said first correspondent transmitting said sets of processed information to said second correspondent; and

d) said second correspondent applying complementary operations of each of said selected cryptographic algorithms in accordance with said predetermined manner to respective ones of said sets of processed information for deriving, from each of said sets of processed information, information related to said common message.

2. The method according to claim 1 wherein said cryptographic algorithms are public key digital signature schemes and said complementary operations perform respective verifications of respective digital signatures.

3. The method according to claim 1 wherein the results of said complementary operations are compared to provide an indication of the authenticity of said sets of processed information.

4. The method according to claim 1, wherein said cryptographic algorithms are hashing functions.

5. The method according to claim 1 wherein said information related to said common message is identically equal to said common message.

6. The method according to claim 1, wherein said information related to said common message is a mathematical representation of said common message.

7. The method according to claim 1 wherein said cryptographic algorithms are digital signature schemes, and wherein said sets of processed information include at least two independently generated digital signatures of said common message.

8. The method according to claim 7 wherein said second correspondent verifies each of said digital signatures.

9. A method of preparing information to be communicated between a first correspondent and a second correspondent over a data communication channel, said method comprising the steps of:

a) selecting a plurality of cryptographic algorithms known to said first correspondent and second correspondent;

b) said first correspondent applying each of said selected cryptographic algorithms to the same information in a common message in a predetermined manner to produce, for that algorithm, a corresponding set of processed information; and

c) said first correspondent transmitting said sets of processed information to said second correspondent.

10. The method according to claim 9 wherein said cryptographic algorithms are digital signature schemes, and wherein said sets of processed information include at least a pair of signatures.

11. A method of verifying the authenticity of a plurality of sets of processed information sent by a first correspondent over a data communication channel to a second correspondent, each set of processed information having been obtained by applying respective one of a plurality of cryptographic algorithms in a predetermined manner to the same information in a common message, said method comprising the steps of:

receiving said plurality of sets of processed information; and

for each set of processed information of said plurality of sets of processed information, applying complementary operations of a respective one of said plurality of cryptographic algorithms to that set of processed information in accordance with said predetermined manner to verify the authenticity of that set of processed information.

12. The method according to claim 11 wherein said cryptographic algorithms are digital signature schemes applied to said common message to obtain corresponding digital signatures, and wherein said verifying the authenticity of said sets of processed information includes verifying each of said digital signatures.

13. A data communication system comprising:

a first cryptographic unit;

a second cryptographic unit; and

a data communication channel therebetween,

wherein;

each of said cryptographic units stores a common plurality of cryptographic algorithms;

said first cryptographic unit is configured for;

selecting two or more of said plurality of cryptographic algorithms,

applying each of said selected algorithms to the same information in a common message in a predetermined manner for producing for that algorithm a corresponding set of processed information; and

transmitting said of processed information to said second cryptographic unit; and

said second cryptographic unit is configured for applying complementary operations of each of said selected cryptographic algorithms in accordance with said predetermined manner to respective ones of said sets of processed information for deriving, from each of said sets of processed information, information related to said common message.

14. The system according to claim 13 wherein said cryptographic algorithms are digital signature schemes.

15. The system according to claim 14 wherein said first cryptographic unit operates to produce a respective digital signature on said common message with each of said cryptographic algorithms such that a plurality of digital signatures is produced.

16. A cryptographic unit for preparing information to be communicated between a first correspondent and a second correspondent over a data communication channel, said cryptographic unit being configured for:

selecting plurality of cryptographic algorithms known to said first correspondent and said second correspondent;

applying each of said selected cryptographic algorithms to the same information in a common message in a predetermined manner for producing for that algorithm a corresponding set of processed information; and

transmitting said sets of processed information to said second correspondent.

17. The cryptographic unit according to claim 16 wherein said cryptographic algorithms are digital signature schemes and said sets of processed information include at least a pair of digital signatures.

18. A cryptographic unit for verifying the authenticity of a plurality of sets of processed information sent by a first correspondent over a data communication channel, each set of processed information having been obtained by applying a respective one of a plurality of cryptographic algorithms in a predetermined manner to the same information in a common message, said cryptographic unit being configured for:

receiving said plurality of sets of processed information; and

for each set of processed information of said plurality of sets of processed information, applying complementary operations of a respective one of said plurality of cryptographic algorithms to that set of processed information in accordance with said predetermined manner to verify the authenticity of that set of processed information.

19. The cryptographic unit according to claim 18 wherein said cryptographic algorithms are digital signature schemes applied to said common message to obtain corresponding digital signatures, and wherein said method further comprises the step of verifying each of said digital signatures.