Biometric controlled key generation

• US 5,680,460 A
• Filed: 08/08/1995
• Issued: 10/21/1997
• Est. Priority Date: 09/07/1994
• Status: Expired due to Term

• Current Assignee: Bioscrypt, Inc. (Advent International Corporation)
• Original Assignee: Mytec Technologies Inc (Advent International Corporation)
• Inventors: Schmidt, Gregory J., Soutar, Colin, Tomko, George J.
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/512,491
• Time in Patent Office: 805 Days
• Field of Search: 380/3, 380/4, 380/23, 380/25, 380/30
• US Class Current: 713/186
• 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 20/40145 Biometric identity checks
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G07C 9/257 electronically G07C9/26 takes precedence
• 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: 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 key generation system is implemented as follows. In an enrolment apparatus, a unique number for use with PIN operated machines or public key cryptography systems is generated by manipulation of fingerprint information of a subscriber. A filter is then generated which is a function both of the Fourier transform of the subscriber'"'"'s fingerprint(s) and of the unique number. This filter is stored on a subscriber card. When the subscriber wishes to generate his key, he inputs his card to a card reader of an apparatus and places his finger(s) on a fingerprint input. The apparatus generates an optical Fourier transform from the fingerprint input. The Fourier transform signal is incident on to a spatial light modulator programmed with the filter information from the card. An inverse transform is generated from the filtered signal and this is used to regenerate the key that will be used as the PIN in a PIN operated device, or as the private key cryptography system.

Claims

1. A biometric controlled key generation system, comprising:

a body part input for generating an information signal bearing biometric information from a body part;

means for reading comparison data from a data carrier, said comparison data comprising private key data encrypted by biometric data; and

means for comparing said information signal with said comparison data for recovering said private key data from said comparison data.

3. The key generation system of claim 1 including means for storing said comparison data on said data carrier, comprising:

a further body part input for generating a further information signal bearing biometric information from said body part;

means to generate a function based on one of said private key and a unique number from which said private key may be derived, said array comprising said private key data;

means to generate biometric data from said further information signal;

means to encrypt said array with said biometric data to generate said comparison data; and

means for storing said comparison data on said data carrier.

4. The key generation system of claim 3 including key generating means for generating a private key from said private key data.

5. The key generation system of claim 4 wherein said means to generate a function is based on said unique number and wherein said key generating means comprises means to recover said unique number from said private key data, and including a pseudo-random number generator responsive to said private key data and a key generator responsive to said pseudo-random number generator and said means to recover said unique number.

6. The key generation system of claim 1 wherein said body part input for generating an information signal comprises optical means for generating an optical information signal and wherein said means for comparing comprises Fourier transform means to obtain a Fourier transform representation of said optical information signal.

7. The key generation system of claim 6 wherein said Fourier transform means comprises optical transform means along a path of said optical information signal and wherein said means for comparing includes (i) a programmable filter responsive to said optical transform means for filtering said Fourier transform representation of said information signal to obtain a filtered Fourier transform representation, (ii) means for programming said filter with said comparison data, and (iii) inverse transform means responsive to said filter to inverse Fourier transform said filtered Fourier transform representation to obtain an inverse transform representation, and including key generating means responsive to said inverse transform means for generating a private key from said private key data.

8. The key generation system of claim 5 wherein said means for comparing comprises Fourier transform means to obtain a Fourier transform representation of said information signal.

9. The key generation system of claim 8 wherein said Fourier transform means comprises transform means along a path of said information signal and wherein said means for comparing includes (i) a programmable filter responsive to said transform means for filtering said Fourier transform representation of said information signal to obtain a filtered Fourier transform representation, (ii) means for programming said filter with said comparison data, and (iii) inverse transform means responsive to said filter to inverse Fourier transform said filtered Fourier transform representation to obtain an inverse transform representation, said key generating means being responsive to said inverse transform means.

10. The key generation system of claim 9 including means to obtain one of said private key and a unique number from which said private key may be derived from said further information signal and wherein said means to generate biometric data from said further information signal comprises means for generating a Fourier transform of said further information signal.

11. The key generation system of claim 10 wherein said means for reading comparison data is also for reading comparison data from a data carrier storing an indication of an intensity of a component of an inverse Fourier transform and wherein said means for comparing is responsive to said data reading means to recover private key data based on said intensity indication as well as based on said inverse transform.

2. A biometric controlled private key encoding system, comprising:

a body part input for generating an information signal bearing biometric information from a body part;

means to generate a function based on one of said private key and a unique number from which said private key may be derived;

means to generate biometric data from said information signal;

means to encrypt said function with said biometric data to generate comparison data; and

means for storing said comparison data on a data carrier.

12. A method for generating a private key, comprising the steps of:

generating an information signal bearing biometric information;

reading comparison data from a data carrier, said comparison data comprising private key data encrypted with biometric data; and

comparing said information signal with said comparison data for recovering said private key data form said comparison data.

14. The method of claim 12 including the steps of:

(a) generating a further information signal bearing biometric information from said body part;

(b) obtaining function generation data comprising one of said private key and a unique number from which said private key may be derived;

(c) generating a function based on step (b);

(d) generating biometric data from said further information signal;

(e) encrypting said function with said biometric data to generate said comparison data; and

(f) storing said comparison data on said data carrier.

15. The method of claim 14 wherein step (b) comprises obtaining said unique number and including the step of pseudo-randomly generating a private key based on said unique number.

16. The method of claim 12 wherein said step of comparing comprises obtaining a Fourier transform representation of said information signal.

17. The method of claim 16 wherein said step of obtaining a Fourier transform comprises transforming said information signal and wherein said step of comparing includes (i) filtering said Fourier transform representation of said information signal with a filter programmed with said comparison data to obtain a filtered Fourier transform representation, and (ii) inverse Fourier transforming said filtered Fourier transform representation to obtain an inverse transform representation, said step of generating a key utilising said inverse transform.

18. The method of claim 14 wherein said step of comparing comprises obtaining Fourier transform representation of said information signal.

19. The method of claim 18 wherein said step of obtaining a Fourier transform comprises transforming said information signal and wherein said step of comparing includes (i) filtering said Fourier transform representation of said information signal with a filter programmed with said comparison data to obtain a filtered Fourier transform representation, and (ii) inverse Fourier transforming said filtered Fourier transform representation to obtain an inverse transform representation, said step of generating a key utilising said inverse transform.

20. The method of claim 18 including the step of obtaining one of said private key and a unique number from which said private key may be derived from said further information signal and wherein said step of generating biometric data form said further information signal comprises generating a Fourier transform of said further information signal.

21. The method of claim 20 wherein said step of reading comparison data comprises reading an indication of an intensity of a component of an inverse Fourier transform and wherein said step of comparing comprises recovering private key data based on said intensity indication as well as based on said inverse transform.

22. The method of claim 12 including the step of utilising said private key data for decrypting a public key encrypted message.

23. The method of claim 12 including the step of utilising said private key data for accessing a PIN operated device.

24. The method of claim 14 wherein said step of generating a function comprises deriving an array based on said function generation data and, for each element of said array, setting an amplitude of an impulse function based on said each element in order to obtain a weighted impulse function array, and wherein the step of encrypting comprises dividing a Fourier transform representation of said weighted impulse function array by said Fourier transform representation of said further information signal.

25. The method of claim 14 wherein said step of generating a function comprises associating a pattern of impulse functions with said function generation data, and wherein the step of encrypting comprises dividing a Fourier transform representation of said associated pattern of impulse functions by said Fourier transform representation of said further information signal.

26. The method of claim 14 wherein said step of generating a function comprises associating a pattern of impulse functions with said function generation data, deriving an array based on said function generation data and, for each element of said array, setting an amplitude of one impulse function of said pattern of impulse functions based on said each element in order to obtain a weighted impulse function pattern, and wherein the step of encrypting comprises dividing a Fourier transform representation of said weighted impulse function pattern by said Fourier transform representation of said further information signal.

13. A method for encoding a private key, comprising the steps of:

(a) generating an information signal bearing biometric information from a body part;

(b) obtaining function generation data comprising one of a private key and a unique number from which said private key may be derived;

(c) generating an array based on step (b);

(d) generating biometric data form said information signal;

(e) encrypting said function with said biometric data to generate said comparison data; and

(f) storing said comparison data on said data carrier.

27. A biometric controlled key generation system, comprising:

a body part input for generating an information signal bearing biometric information from a body part;

a programmable filter for filtering a function of said biometric information;

means for reading filter data from a data carrier and for programming said programmable filter with said filter data, said filter data comprising data for use in generating a private key, said private key generating data being encrypted by biometric data; and

means responsive to an output of said filter for recovering said private key generating data.

28. The key generation system of claim 27 including Fourier transform means for obtaining a Fourier transform representation of said biometric information, said function of said biometric information comprising said Fourier transform representation such that said programmable filter is for filtering said Fourier transform representation of said biometric information.

29. The key generation system of claim 28 wherein said body part input is for generating an optical information signal and said Fourier transform means comprises optical Fourier transform means along a path of said optical information signal for obtaining an optical Fourier transform representation of said biometric information, said programmable filter being responsive to said optical transform means for filtering an optical Fourier transform representation of said biometric information to obtain a filtered Fourier transform representation.

30. The key generation system of claim 28 wherein said Fourier transform means comprises digital Fourier transform means for obtaining a digital Fourier transform representation of said biometric information, said programmable filter being responsive to said digital transform means for filtering a digital Fourier transform representation of said biometric information to obtain a filtered Fourier transform representation.

31. The key generation system of claim 29 including inverse transform means responsive to said programmable filter for obtaining an inverse Fourier transform representation of said filtered Fourier transform representation and including key generating means responsive to said inverse transform means of regenerating a private key from said private key generating data.

32. The key generation system of claim 31 including key generating means for generating a private key from said private key generating data.

33. The key generation system of claim 32 wherein said key generating means comprises means to recover a unique number from said private key generating data, and including a pseudo-random number generator responsive to said means to recover said unique number and a key generator responsive to said pseudo-random number generator and said means to recover said unique number.

34. The key generation system of claim 31 wherein said body part input comprises a fingerprint input for receiving at least one finger of a user.

35. The key generation system of claim 34 wherein said data reading means comprises a card reader.

36. The key generation system of claim 35 wherein said Fourier transform means comprises a Fourier transform lens said programmable filter comprises a programmable spatial light modulator, and said inverse transform means comprises a lens.

37. The key generation system of claim 31 wherein said data filter reading means includes means for reading data form a data carrier storing an indication of an intensity and wherein said unique number generator is responsive to said data reading means to generate a unique number from said intensity indication as well as from said inverse transform.

38. The key generation system of claim 32, adapted for use as a public key cryptographic system, comprising user controlled selection means and wherein said key generating means is responsive to said selection means for selectively generating one of said private key for decrypting a message and a public key for encrypting a message.

39. The key generation system of claim 38 including a public key decryption system for storing an encrypted message and, responsive to any private key generated by said key generating means, for attempting to decrypt said encrypted message with said private key.

40. A biometric controlled private key encoding system, comprising:

a body part input for generating an information signal bearing biometric information from a body part;

means to generate a function based on one of a private key or a unique number from which said private key may be derived;

means to generate biometric data from said information signal;

means to encrypt said function with said biometric data to generate filter data for a programmable filter; and

means for storing said filter data on a data carrier.

41. The key generation system of claim 40 wherein said means to generate biometric data from said information signal comprises means for generating a Fourier transform representation of said biometric information.

42. The key generation system of claim 41 wherein said means to generate a function comprises means to generate a Fourier transform representation based on one of said private key and said unique number and wherein said means to encrypt said function comprises means to divide said Fourier transform representation based on one of said private key and said unique number by said Fourier transform representation of said biometric information to obtain said filter data.

43. A method for generating a private key, comprising the steps of:

generating an information signal bearing biometric information;

reading filter data form a data carrier, said filter data comprising data for use in generating a private key encrypted with biometric data;

programming a programmable filter with said filter data; and

recovering private key generating data form said filter data by filtering a function of said biometric information with said programmed filter.

44. The method of claim 43 including the step of obtaining a Fourier transform representation of said biometric information, said Fourier transform representation of said biometric information comprising said function of said biometric information.

45. The method of claim 44 wherein the step of recovering private key generating data includes the step of inverse Fourier transforming data filtered by said filtering step.

46. The method of claim 45 wherein the step of recovering private key generating data includes the step of reading an indication of an intensity indication from said data carrier.

47. The method of claim 43 including the step of utilising said private key generating data for decrypting a public key encrypted message.

48. The method of claim 43 including the step of utilising said private key generating data for accessing a PIN operated device.

49. A method for encoding a private key, compromising the steps of:

(a) generating an information signal bearing biometric information from a body part;

(b) generating function generation data comprising one of a private key or a unique number from which said private key may be derived;

(c) obtaining a function based on said function generation data;

(d) generating biometric data from said information signal;

(e) encrypting said function with said biometric data to generate filter data for a programmable filter; and

(f) storing said filter data on a data carrier.

50. The method of claim 49 wherein said step of generating biometric data comprises obtaining a Fourier transform representation of said biometric information.

51. The method of claim 50 wherein the step of obtaining a function comprises obtaining a Fourier transform representation based on said function generation data and wherein the step of encrypting said function comprises dividing said Fourier transform representation of said function by said Fourier transform representation of said biometric information to obtain said filter data.

52. The method of claim 51 wherein said step of obtaining a Fourier transform representation based on said function generation data comprises generating an array from said function generation data, choosing a set of impulse functions based on said array, and obtaining a Fourier transform from said set.

53. The method of claim 52 wherein the step of choosing a set of impulse functions comprises, for each element of said array, setting an amplitude of an impulse function based on said each element in order to obtain a set of weighted impulse functions.

54. The method of claim 50 wherein said step of choosing a set of impulse functions comprises associating a pattern of impulse functions with each element of said array of function generation data.

55. The method of claim 50 wherein step (b) comprises obtaining said unique number and including the step of pseudo-randomly generating a private key based on said unique number.