Fuzzy Keys

• US 20090016535A1
• Filed: 06/13/2008
• Published: 01/15/2009
• Est. Priority Date: 06/13/2007
• Status: Abandoned Application

• Current Assignee: Ingenia Holdings Limited
• Original Assignee: Ingenia Holdings Limited
• Inventors: Cowburn, Russell Paul
• Application Number:
  US12/139,238
• Publication Number:
  US 20090016535A1
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 9/0618 Block ciphers, i.e. encrypting groups of characters of a plain text message using fixed encryption transformation
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics

Abstract

A method can be provided for performing encryption using a fuzzy key. The method can comprise generating a message, dividing a fuzzy key into a plurality of blocks; and generating an encrypted message by selecting a block from the fuzzy key corresponding to a bit position or bit pattern in the message.

Claims

1. A method for performing encryption using a fuzzy key, the method comprising:

generating a message;

dividing a fuzzy key into a plurality of blocks;

generating an encrypted message by selecting a block from the fuzzy key corresponding to a bit position or bit pattern in the message.

2. The method of claim 1, wherein the generating comprises selecting for each bit position value or bit pattern in the message a different block from the fuzzy key, on the basis of the value at the bit position or on the basis of a predetermined association with the bit pattern.

3. The method of claim 1, further comprising adding error correction coding to the message prior to encryption.

4. The method of claim 1, wherein the message is a session key for a symmetrical encryption algorithm or a public key for an asymmetric encryption algorithm.

5. The method of claim 1, wherein the fuzzy key is a biometric type signature.

6. The method of claim 5, wherein the biometric type signature is representative of a surface texture of an identifier article.

7. The method of claim 1, further comprising:

dividing a second fuzzy key into a plurality of blocks;

wherein the number of blocks of the first and second fuzzy keys is equal to or greater than the number of bits in the message, and wherein the generating comprises, for each respective bit of the message selecting between the respective blocks of the first and second fuzzy keys in dependence upon the value of the bit of the message.

8. The method of claim 7, wherein the second fuzzy key is the bitwise logical NOT of the first fuzzy key.

9. The method of claim 7, wherein the first and second fuzzy keys are created from different regions of a single identifier article.

10. The method claim 1, further comprising:

dividing the message into blocks of n bits each;

wherein the number of blocks of the fuzzy key is determined as 2ⁿ and each block is associated with the n bit block number; and

wherein the generating is performed by selecting for each block in the message, the block from the fuzzy key having the block number corresponding to the bit pattern of the message block.

11. A system for performing encryption using a fuzzy key, the system comprising:

a key handler operable to divide a fuzzy key into a plurality of blocks; and

a generator operable to generate an encrypted message by selecting a block from the fuzzy key corresponding to a bit position or bit pattern in a message to be encrypted.

12. The system of claim 11, further comprising an error correction generator operable to add error correction coding to the message prior to encryption.

13. The system of claim 11, wherein the message is a session key for a symmetrical encryption algorithm or a public key for an asymmetric encryption algorithm.

14. The system of claim 11, wherein the fuzzy key is a biometric type signature.

15. The system of claim 14, wherein the biometric type signature is representative of a surface texture of an identifier article.

16. The system of claim 11, wherein:

the key handler is further operable to divide a second fuzzy key into a plurality of blocks;

wherein the number of blocks of the first and second fuzzy keys is equal to or greater than the number of bits in the message, and wherein the generator or operable, for each respective bit of the message to select between the respective blocks of the first and second fuzzy keys in dependence upon the value of the bit of the message.

17. The system of claim 16, wherein the second fuzzy key is the bitwise logical NOT of the first fuzzy key.

18. The system of claim 16, wherein the first and second fuzzy keys are created from different regions of a single identifier article.

19. The system of claim 11, wherein:

the key handler is operable to divide the message into blocks of n bits each;

wherein the number of blocks of the fuzzy key is determined as 2ⁿ and each block is associated with the n bit block number; and

wherein the generator is operable to select for each block in the message, the block from the fuzzy key having the block number corresponding to the bit pattern of the message block.

20. A method for performing decryption using a fuzzy key, the method comprising:

receiving a message encrypted using a fuzzy key;

dividing a fuzzy key generated from the same source as a fuzzy key used to encrypt the message into a plurality of blocks; and

comparing each block of the received message to a respective block of the fuzzy key to determine a value for a bit position or bit pattern in the message.

21. The method of claim 20, further comprising performing error correction processing on the message following decryption.

22. The method of claim 20, wherein the message is a session key for a symmetrical encryption algorithm or a public key for an asymmetric encryption algorithm.

23. The method of claim 20, wherein the fuzzy key is a biometric type signature.

24. The method of claim 23, wherein the biometric type signature is representative of a surface texture of an identifier article.

25. The method of claim 20, further comprising:

dividing a second fuzzy key generated from the same source as a fuzzy key used to encrypt the message into a plurality of blocks;

wherein the number of blocks of the first and second fuzzy keys is equal to or greater than the number of bits in the message, and wherein the comparing comprises, for each respective block of the encrypted message selecting between the respective blocks of the first and second fuzzy keys in dependence upon a comparison result between the encrypted message block and each fuzzy key block, wherein the bit value of the message bit is determined in dependence upon the selected fuzzy key block.

26. The method of claim 25, wherein the second fuzzy key is the bitwise logical NOT of the first fuzzy key.

27. The method of claim 25, wherein the first and second fuzzy keys are created from different regions of a single identifier article.

28. The method of claim 20, wherein the comparing further comprises comparing a block of the encrypted message to each block of the fuzzy key to determine a best match block from the fuzzy key, wherein the value of a bit pattern in the message is recovered as being the block number of the best match block form the fuzzy key.

29. A system for performing decryption using a fuzzy key, the system comprising:

a receiver operable to receive a message encrypted using a fuzzy key;

a key handler operable to divide a fuzzy key generated from the same source as a fuzzy key used to encrypt the message into a plurality of blocks; and

a comparator operable to compare each block of the received message to a respective block of the fuzzy key to determine a value for a bit position or bit pattern in the message.

30. The system of claim 29, further comprising an error correction processor operable to perform error correction processing on the message following decryption.

31. The system of claim 29, wherein the message is a session key for a symmetrical encryption algorithm or a public key for an asymmetric encryption algorithm.

32. The system of claim 29, wherein the fuzzy key is a biometric type signature.

33. The system of claim 32, wherein the biometric type signature is representative of a surface texture of an identifier article.

34. The system of claim 29, wherein:

the key handler is operable to divide a second fuzzy key generated from the same source as a fuzzy key used to encrypt the message into a plurality of blocks;

wherein the number of blocks of the first and second fuzzy keys is equal to or greater than the number of bits in the message, and wherein the comparator is operable to, for each respective block of the encrypted message select between the respective blocks of the first and second fuzzy keys in dependence upon a comparison result between the encrypted message block and each fuzzy key block, wherein the bit value of the message bit is determined in dependence upon the selected fuzzy key block.

35. The system of claim 34, wherein the second fuzzy key is the bitwise logical NOT of the first fuzzy key.

36. The system of claim 34, wherein the first and second fuzzy keys are created from different regions of a single identifier article.

37. The system of claim 34, wherein the comparator is operable to compare a block of the encrypted message to each block of the fuzzy key to determine a best match block from the fuzzy key, wherein the value of a bit pattern in the message is recovered as being the block number of the best match block form the fuzzy key.

38. A method for transmitting a message, the method comprising:

encrypting a message using a fuzzy key, the encrypting comprising dividing a fuzzy key into a plurality of blocks, and generating an encrypted message by selecting a block from the fuzzy key corresponding to a bit position or bit pattern in the message;

transmitting the encrypted message; and

decrypting the message using a fuzzy key, the decrypting comprising dividing a fuzzy key, generated from the same source as the fuzzy key used to encrypt the message, into a plurality of blocks, and comparing each block of the received message to a respective block of the fuzzy key to determine a value for a bit position or bit pattern in the message.