Pseudorandom composition-based cryptographic authentication process

• US 5,649,014 A
• Filed: 10/02/1995
• Issued: 07/15/1997
• Est. Priority Date: 08/22/1994
• Status: Expired due to Fees

• Current Assignee: UT Automotive Dearborn, Inc.
• Original Assignee: United Technologies Automotive, Inc. (Lear Corporation)
• Inventors: Finn, Alan M., Koopman, Philip J. Jr., LaBarre, Robert E.
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/537,487
• Time in Patent Office: 652 Days
• Field of Search: 380/3, 380/4, 380/23, 380/24, 380/25, 380/28, 380/42, 380/44
• US Class Current: 380/28
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 2209/84 Vehicles
• CPC Class Codes: H04L 9/002 Countermeasures against attacks on cryptographic mechanisms network architectures or network communication protocols for protection against malicious traffic H04L63/1441
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

The pseudorandom process iteratively applies a selected CRC encryption process on the information to be encrypted. The encryption process is selected by testing one of the digits comprising the number to be encrypted. A first encryption process is used if the tested digit is a 1; a second encryption process is used if the tested digit is a 0. The process is repeated a plurality of times, e.g. once for each digit in the number to be encrypted, resulting in a highly encrypted value that is not easily reverse engineered by chosen or known plaintext attack.

Claims

1. A method of encrypting digital information comprising:

representing said digital information as a set of binary digits, N;

(a) testing one of the binary digits to determine if the digit is a 1 or a 0;

(b) applying a first encryption process on said digital information if the digit is a 1 to produce an altered set of digital information;

(c) applying a second encryption process on said digital information if the digit is a 0 to produce an altered set of digital information;

(d) replacing said digital information with said altered set of digital information;

(e) repeating steps (a) through (d), testing a different one of said binary digits in performing step (a).

2. The method of claim 1 wherein said first encryption process is an enhanced CRC process.

3. The method of claim 1 wherein said second encryption process is an enhanced CRC process.

4. The method of claim 1 further comprising performing a third encryption process on said set of binary digits prior to said step of testing the binary digits.

5. The method of claim 1 wherein step (e) is performed iteratively over each digit in said set of digits.

6. The method of claim 1 wherein a plurality of binary digits are tested in step (a).

7. A system for encrypting digital information, the digital information comprising at least a first and a second binary digit, the system comprising:

means for determining whether said first binary digit is a logic 1 or a logic 0;

means for encrypting the digital information according to a first encryption process if said first binary digit is a logic 1 or a second encryption process if said first binary digit is a logic 0 to produce an altered set of digital information; and

means for replacing said digital information with said altered set of digital information.

8. The system of claim 7, further comprising:

means for determining whether said second binary digit is a logic 1 or a logic 0;

means for encrypting said altered set of digital information according to a third encryption process if said second binary digit is a logic 1 or a fourth encryption process if said second binary digit is a logic 0 to produce a second altered set of digital information; and

means for replacing said altered set of digital information with said second altered set of digital information.

9. The system of claim 8, wherein said first or said second or said third or said fourth encryption process comprises an enhanced CRC process.

10. The system of claim 7, further comprising:

means for performing a fifth encryption process on the first and second binary digits to encrypt and input the digital information to said means for determining whether said first binary digit is a logic 1 or a logic 0.

11. The system of claim 8, further comprising:

means for performing a sixth encryption process on the first and second binary digits to encrypt and input said altered set of digital information to said means for determining whether said second binary digit is a logic 1 or a logic 0.

12. The system of claim 8, wherein the digital information further comprises a third binary digit, and further comprising:

means for determining whether said third binary digit is a logic 1 or a logic 0;

means for encrypting said second altered set of digital information according to a seventh encryption process if said third binary digit is a logic 1 or an eighth encryption process if said third binary digit is a logic 0 to produce a third altered set of digital information; and

means for replacing said second altered set of digital information with said third altered set of digital information.

13. The system of claim 12, wherein said seventh or said eighth encryption process comprises an enhanced CRC process.

14. The system of claim 8, wherein said means for determining whether said first binary digit is a logic 1 or a logic 0, said means for determining whether said second binary digit is a logic 1 or a logic 0, and said means for determining whether said third binary digit is a logic 1 or a logic 0 are realized by a single means for determining device.

15. The system of claim 7, further comprising:

means for authenticating said altered set of digital information; and

means for performing a security function if said altered set of digital information authentication is valid.

16. A system for encrypting digital information, the digital information comprising at least a first and a second binary digit, the system comprising:

a digital tester for testing whether said first binary digit is a logic 1 or a logic 0;

an encryptor for encrypting the digital information according to a first encryption method if said first binary digit is a logic 1 or according to a second encryption method if said first binary digit is a logic 0 to produce an altered set of digital information; and

a replacing device for replacing said digital information with said altered set of digital information.

17. The system of claim 16, further comprising:

a second digital tester for determining whether said second binary digit is a logic 1 or a logic 0;

a second encryptor for encrypting said altered set of digital information according to a third encryption process if said second binary digit is a logic 1 or according to a fourth encryption process if said second binary digit is a logic 0 to produce a second altered set of digital information; and

a second replacing device for replacing said altered set of digital information with said second altered set of digital information.

18. The system of claim 17, wherein said first and second digital tester are realized by a singular device, said first and second encryptor are realized by a singular device, and said first and second repeater are realized by a singular device.

19. The system of claim 17, wherein said first or said second or said third or said fourth encryption process comprises an enhanced CRC process.

20. The system of claim 16, further comprising:

a third encryptor for encrypting said at least a first and a second binary digit according to encrypt and input the digital information to said digital tester for testing whether said first binary digit is a logic 1 or a logic 0.

21. The system of claim 17, further comprising:

a fourth encryptor for encrypting said at least a first and a second binary digit according to encrypt and input said altered set of digital information to said second digital tester for testing whether said second binary digit is a logic 1 or a logic 0.

22. The system of claim 17, wherein the digital information further comprises a third binary digit, and further comprising:

a third digital tester for determining whether said third binary digit is a logic 1 or a logic 0;

a fifth encryptor for encrypting said second altered set of digital information according to a seventh encryption process if said third binary digit is a logic 1 or an eighth encryption process if said third binary digit is a logic 0 to produce a third altered set of digital information; and

a replacing device for replacing said second altered set of digital information with said third altered set of digital information.

23. The system of claim 22, wherein said fifth or said sixth or said seventh or said eighth encryption process comprises an enhanced CRC process.

24. The system of claim 22, wherein said digital tester for determining whether said first binary digit is a logic or a logic 0, said second digital tester for determining whether said second binary digit is a logic 1 or a logic 0, and said third tester for determining whether said third binary digit is a logic 1 or a logic 0 are realized by a singular device.

25. The system of claim 16, further comprising:

an authenticator for authenticating said altered set of digital information; and

a system for performing a security function when said altered set of digital information authentication is valid.

26. A pseudorandom composition based cryptographic authentication system for encrypting digital information represented as a number of binary digits, the pseudorandom composition based cryptographic authentication system comprising:

a selector for selecting a binary digit of the number corresponding with a counter, said counter having a value pointing to said selected binary digit of said plurality;

a comparator for comparing said counter value with the number;

a digital tester for testing whether said selected binary digit of the number is a logic 1 or a logic 0;

an encryptor for encrypting the digital information according to a first encryption method if said binary digit of said plurality is a logic 1 or according to a second encryption method if said binary digit is a logic 0 to produce an altered set of digital information;

a copying device for copying said altered set of digital information into said digital information when the number is greater than said counter value, said copying device incrementing said counter value upon copying said altered set of digital information; and

a feedback loop for restarting the pseudorandom composition based cryptographic authentication system to enable each binary digit of the number to be individually processed the number of times such that said selector selects a further binary digit of the number, said comparator compares the number with said counter value, said encryptor encrypts, said copying device copies, and said counter value is incremented, until said counter value is equal to the number.