Apparatus and method for preventing fraudulent calls in a wireless telephone system using destination and fingerprint analysis

• US 5,970,405 A
• Filed: 02/28/1997
• Issued: 10/19/1999
• Est. Priority Date: 02/28/1997
• Status: Expired due to Fees

• Current Assignee: Cellular Technical Services Co., Inc. (Asensus Surgical, Inc.)
• Original Assignee: Cellular Technical Services Co., Inc. (Asensus Surgical, Inc.)
• Inventors: McKernan, Randolph W., Wilburn, Howard L., Green, Evan R., Stanhope, David M., Kaplan, Dmitry
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Gesesse, Tilahun
• Application Number:
  US08/810,318
• Time in Patent Office: 963 Days
• Field of Search: 455/410, 455/411, 455/432, 455/435, 455/437, 455/456, 455/67.1, 455/67.7, 455/67.4
• US Class Current: 455/410
• CPC Class Codes: H04W 12/126 Anti-theft arrangements, e.g. protection against subscriber identity module [SIM] cloning

Abstract

A system and method for the detection of fraudulent use of a wireless telephone system includes a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint of the unauthenticated wireless telephone. The system maintains a valid destination list specific for each authorized wireless telephone. Each valid destination list contains destinations considered to be valid for that particular authorized wireless telephone. When an unauthenticated wireless telephone transmits a call request containing a destination, the system classifies the call as valid when the destination is in the valid destination list for the authorized wireless telephone regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent. The system may bypass or terminate the fingerprint analysis, or simply ignore the result of the fingerprint analysis by the fingerprint analyzer. The system also maintains an invalid destination list specific for each authorized wireless telephone with destinations considered to be invalid for that particular authorized wireless telephone. Calls to such destinations are blocked. The system further maintains a suspicious destination list containing destinations considered to be potentially fraudulent. When the destination contained in the call request is in the suspicious destination list, the fingerprint analysis is performed with a higher threshold to require a closer match between a fingerprint of the unauthenticated wireless telephone and a stored fingerprint of the corresponding authorized wireless telephone.

Claims

1. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a first threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone;

classifying the call as valid when the designated destination is determined to be in the corresponding locally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent;

determining whether the designated destination is in the suspicious data; and

when the designated destination is determined to be in the suspicious data, performing a fingerprint analysis by the fingerprint analyzer using a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

2. The method according to claim 1, further comprising the steps of:

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone; and

classifying the call as invalid when the designated destination is determined to be in the corresponding locally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

3. The method according to claim 2, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a first predetermined group of users;

determining whether the designated destination is in the globally valid data; and

classifying the call as valid when the designated destination is determined to be in the globally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

4. The method according to claim 3, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a second predetermined group of users;

determining whether the designated destination is in the globally invalid data; and

classifying the call as invalid when the designated destination is determined to be in the globally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

5. The method according to claim 4 wherein the globally invalid data includes all destinations within one of a selected office code, area code, and country code.

6. The method according to claim 1, further including when the call is classified as valid, the step of preventing the fingerprint analyzer from performing a fingerprint analysis to identify the unauthenticated wireless telephone as authorized or fraudulent.

7. The method according to claim 1, further including when the call is classified as valid, the step of overriding an identification by the fingerprint analyzer that the unauthenticated wireless telephone is fraudulent.

8. The method according to claim 1, further including when the call is classified as valid, the step of allowing the call.

9. The method according to claim 2, further comprising the step of adding a new destination to the locally invalid data corresponding to the specific authorized wireless telephone based on the payment record for that new destination of a user of the specific authorized wireless telephone.

10. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a first threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the suspicious data; and

when the designated destination is determined to be in the suspicious data, performing a fingerprint analysis by the fingerprint analyzer using a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

11. The method according to claim 10, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a predetermined group of users;

determining whether the designated destination is in the globally valid data; and

classifying the call as valid when the designated destination is determined to be in the globally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

12. The method according to claim 11 wherein the predetermined group of users includes all users.

13. The method according to claim 10, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data; and

classifying the call as invalid when the designated destination is determined to be in the globally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

14. The method according to claim 10, further comprising the steps of:

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone; and

classifying the call as invalid when the designated destination is determined to be in the corresponding locally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

15. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone;

classifying the call as valid when the designated destination is determined to be in the corresponding locally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone; and

classifying the call as invalid when the designated destination is determined to be in the corresponding locally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

16. The method according to claim 15, further including when the call is classified as valid, the step of preventing the fingerprint analyzer from performing a fingerprint analysis to identify the unauthenticated wireless telephone as authorized or fraudulent.

17. The method according to claim 15, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data; and

classifying the call as invalid when the designated destination is determined to be in the globally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

18. The method according to claim 15 wherein the fingerprint analyzer utilizes a first threshold for the fingerprint analysis, further comprising the steps of:

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

determining whether the designated destination is in the suspicious data; and

when the designated destination is determined to be in the suspicious data, performing a fingerprint analysis by the fingerprint analyzer using a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

19. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone; and

classifying the call as valid when the designated destination is determined to be in the corresponding locally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

20. The method according to claim 19, further comprising the step of when the call is classified as valid, preventing the fingerprint analyzer from performing a fingerprint analysis of the unauthenticated wireless telephone.

21. The method according to claim 19, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a predetermined group of users;

determining whether the designated destination is in the globally valid data; and

classifying the call as valid when the designated destination is determined to be in the globally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

22. The method according to claim 21 wherein the predetermined group of users includes all users.

23. The method according to claim 19, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data; and

classifying the call as invalid when the designated destination is determined to be in the globally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

24. The method according to claim 23 wherein the predetermined group of users includes all users.

25. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a selected threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone;

setting a first threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally valid data;

determining whether the designated destination is in the suspicious data;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the suspicious data; and

performing a fingerprint analysis by the fingerprint analyzer using the first threshold if the designated destination is determined to be in the corresponding locally valid data and using the second threshold if the designated destination is determined to be in the suspicious data, with the first and second thresholds each being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

26. The method according to claim 25, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data and determining a second confidence value if the designated destination is determined to be in the suspicious data, and wherein the first and second thresholds are set based upon the determined value of the first and second confidence values, respectively.

27. The method according to claim 25, further comprising the steps of:

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone;

setting a third threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the third threshold if the designated destination is determined to be in the corresponding locally invalid data, with the third threshold being selected to require a corresponding selected matching between the transmission characteristics of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

28. The method according to claim 27, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data, determining a second confidence value if the designated destination is determined to be in the suspicious data, and determining a third confidence value if the designated destination is determined to be in the corresponding locally invalid data, and wherein the first, second and third thresholds are set based upon the determined value of the first, second and third confidence values, respectively.

29. The method according to claim 27, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a first predetermined group of users;

determining whether the designated destination is in the globally valid data;

setting a fourth threshold different from the selected threshold if the designated destination is determined to be in the globally valid data; and

performing a fingerprint analysis by the fingerprint analyzer using the fourth threshold if the designated destination is determined to be in the globally valid data, with the fourth threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

30. The method according to claim 29, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data, determining a second confidence value if the designated destination is determined to be in the suspicious data, determining a third confidence value if the designated destination is determined to be in the corresponding locally invalid data, and determining a fourth confidence value if the designated destination is determined to be in the globally valid data, and wherein the first, second, third and fourth thresholds are set based upon the determined value of the first, second, third and fourth confidence values, respectively.

31. The method according to claim 29, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a second predetermined group of users;

determining whether the designated destination is in the globally invalid data;

setting a fifth threshold different from the selected threshold if the designated destination is determined to be in the globally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the fifth threshold if the designated destination is determined to be in the globally invalid data, with the fifth threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthorized wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

32. The method according to claim 30, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data, determining a second confidence value if the designated destination is determined to be in the suspicious data, determining a third confidence value if the designated destination is determined to be in the corresponding locally invalid data, determining a fourth confidence value if the designated destination is determined to be in the globally valid data, and determining a fifth confidence value if the designated destination is determined to be in the globally invalid data, and wherein the first, second, third, fourth and fifth thresholds are set based upon the determined value of the first, second, third, fourth and fifth confidence values, respectively.

33. The method according to claim 31 wherein the globally invalid data includes all destinations within one of a selected office code, area code, and country code.

34. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a selected threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the suspicious data;

setting a first threshold different from the selected threshold if the designated destination is determined to be in the suspicious data; and

performing a fingerprint analysis by the fingerprint analyzer using the first threshold if the designated destination is determined to be in the suspicious data, with the first threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

35. The method of claim 34, further comprising the steps of determining a confidence value if the designated destination is determined to be in the suspicious data, and wherein the first threshold is set based upon the determined value of the confidence value.

36. The method according to claim 34, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a predetermined group of users;

determining whether the designated destination is in the globally valid data;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the globally valid data; and

performing a fingerprint analysis by the fingerprint analyzer using the second threshold if the designated destination is determined to be in the globally valid data, with the second threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

37. The method of claim 36, further comprising the steps of determining a confidence value if the designated destination is determined to be in the globally valid data, and wherein the second threshold is set based upon the determined value of the confidence value.

38. The method according to claim 36 wherein the predetermined group of users includes all users.

39. The method of claim 36 wherein the second threshold is less than the selected threshold.

40. The method according to claim 34, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the globally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the second threshold if the designated destination is determined to be in the globally invalid data, with the second threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

41. The method of claim 40, further comprising the steps of determining a confidence value if the designated destination is determined to be in the globally invalid data, and wherein the second threshold is set based upon the determined value of the confidence value.

42. The method according to claim 34, further comprising the steps of:

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the second threshold if the designated destination is determined to be in the corresponding locally valid data, with the second threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

43. The method of claim 42, further comprising the steps of determining a confidence value if the designated destination is determined to be in the corresponding locally invalid data, and wherein the second threshold is set based upon the determined value of the confidence value.

44. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a selected threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

maintaining a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone;

setting a first threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally valid data;

determining whether the designated destination is in the locally invalid data corresponding to the identified authorized wireless telephone;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the first threshold if the designated destination is determined to be in the corresponding locally valid data and using the second threshold if the designated destination is determined to be in the corresponding locally invalid data, with the first and second thresholds each being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

45. The method according to claim 44, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data and determining a second confidence value if the designated destination is determined to be in the corresponding locally invalid data, and wherein the first and second thresholds are set based upon the determined value of the first and second confidence values, respectively.

46. The method according to claim 44, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data;

setting a third threshold different from the selected threshold if the designated destination is determined to be in the globally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the third threshold if the designated destination is determined to be in the globally invalid data, with the third threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

47. The method according to claim 46, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data, determining a second confidence value if the designated destination is determined to be in the corresponding locally invalid data, and determining a third confidence value if the designated destination is determined to be in the globally invalid data, and wherein the first, second and third thresholds are set based upon the determined value of the first, second and third confidence values, respectively.

48. The method according to claim 44, further comprising the steps of:

maintaining a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

determining whether the designated destination is in the suspicious data;

setting a third threshold different from the selected threshold if the designated destination is determined to be in the suspicious data; and

performing a fingerprint analysis by the fingerprint analyzer using the third threshold if the designated destination is determined to be in the suspicious data, with the third threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

49. The method according to claim 48, further comprising the steps of determining a first confidence value if the designated destination is determined to be in the corresponding locally valid data, determining a second confidence value if the designated destination is determined to be in the corresponding locally invalid data, and determining a third confidence value if the designated destination is determined to be in the suspicious data, and wherein the first, second and third thresholds are set based upon the determined value of the first, second and third confidence values, respectively.

50. A method of preventing fraudulent calls by users of a wireless telephone system including a fingerprint analyzer that identifies an unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a selected threshold for the fingerprint analysis, the method comprising the steps of:

maintaining a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

receiving from an unauthenticated wireless telephone a call request containing a designated destination and identifying an authorized wireless telephone;

determining whether the designated destination is in the locally valid data corresponding to the identified authorized wireless telephone;

setting a first threshold different from the selected threshold if the designated destination is determined to be in the corresponding locally valid data; and

performing a fingerprint analysis by the fingerprint analyzer using the first threshold if the designated destination is determined to be in the corresponding locally valid data, with the first threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

51. The method of claim 50, further comprising the steps of determining a confidence value if the designated destination is determined to be in the corresponding locally valid data, and wherein the first threshold is set based upon the determined value of the confidence value.

52. The method according to claim 50, further comprising the steps of:

maintaining a globally valid data containing at least one destination considered to be valid for a predetermined group of users;

determining whether the designated destination is in the globally valid data;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the globally valid data; and

performing a fingerprint analysis by the fingerprint analyzer using the second threshold if the designated destination is determined to be in the globally valid data, with the second threshold being selected to require a corresponding selected matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

53. The method of claim 52, further comprising the steps of determining a confidence value if the designated destination is determined to be in the globally valid data, and wherein the second threshold is set based upon the determined value of the confidence value.

54. The method according to claim 50, further comprising the steps of:

maintaining a globally invalid data containing at least one destination considered to be invalid for a predetermined group of users;

determining whether the designated destination is in the globally invalid data;

setting a second threshold different from the selected threshold if the designated destination is determined to be in the globally invalid data; and

performing a fingerprint analysis by the fingerprint analyzer using the second threshold if the designated destination is determined to be in the globally invalid data, with the second threshold being selected to require a corresponding selected matching between transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the identified authorized wireless telephone in order to identify the unauthenticated wireless telephone as authorized.

55. The method of claim 54, further comprising the steps of determining a confidence value if the designated destination is determined to be in the globally invalid data, and wherein the second threshold is set based upon the determined value of the confidence value.

56. A system for preventing fraudulent calls by users of a wireless telephone network comprising:

a storage device operable to store a designated destination contained in a call request from an unauthenticated wireless telephone, the storage device operable to store a plurality of locally valid data, each locally valid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be valid for the corresponding specific authorized wireless telephone;

a fingerprint analyzer that identifies the unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone; and

a processor connected to the fingerprint analyzer and the storage device, and operable to determine whether the designated destination is in the locally valid data for the corresponding authorized wireless telephone and to classify the call as valid when the designated destination is determined to be in the corresponding locally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

57. The system according to claim 56 wherein when the designated destination is determined to be in the corresponding locally valid data, the processor prevents the fingerprint analyzer from performing a fingerprint analysis to identify the unauthenticated wireless telephone as authorized or fraudulent.

58. The system according to claim 56 wherein:

the fingerprint analyzer utilizes a first threshold for the fingerprint analysis;

the storage device stores a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones; and

the processor determines whether the designated destination is in the suspicious data and when the designated destination is determined to be in the suspicious data, the processor executes through the fingerprint analyzer a fingerprint analysis using a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the corresponding authorized wireless telephone.

59. The system according to claim 56 wherein:

the storage device stores a globally valid data containing at least one destination considered to be valid for all users; and

the processor determines whether the designated destination is in the globally valid data and classifies the call as valid when the designated destination is determined to be in the globally valid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as fraudulent.

60. The system according to claim 56 wherein:

the storage device stores a globally invalid data containing at least one destination considered to be invalid for all users; and

the processor determines whether the designated destination is in the globally invalid data and classifies the call as invalid when the designated destination is determined to be in the globally invalid data regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

61. The system according to claim 56 wherein:

the storage device stores a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone; and

the processor determines whether the designated destination is in the locally invalid data corresponding to the unauthenticated wireless telephone and classifies the call as invalid when the designated destination is determined to be in the corresponding locally invalid data for the corresponding authorized wireless telephone regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.

62. A system for preventing fraudulent calls by users of a wireless telephone network, comprising:

a storage device operable to store a designated destination contained in a call request from an unauthenticated wireless telephone, the storage device operable to store a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones;

a fingerprint analyzer that identifies the unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a first threshold and a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the corresponding authorized wireless telephone; and

a processor connected to the fingerprint analyzer and the storage device, and operable to determine whether the designated destination is in the suspicious data and to execute through the fingerprint analyzer a fingerprint analysis using the second threshold when the designated destination is determined to be in the suspicious data.

63. A system for preventing fraudulent calls in a wireless telephone system comprising:

a storage device operable to store a designated destination contained in a call request from an unauthenticated wireless telephone, the storage device operable to store a suspicious data containing at least one destination considered to be called by fraudulent wireless telephones and to store a plurality of locally invalid data, each locally invalid data corresponding to a specific authorized wireless telephone and containing at least one destination considered to be invalid for the corresponding specific authorized wireless telephone;

a fingerprint analyzer that identifies the unauthenticated wireless telephone as authorized or fraudulent based on a fingerprint analysis of comparing a transmission characteristic of the unauthenticated wireless telephone with a stored fingerprint of a corresponding authorized wireless telephone using a first threshold and a second threshold higher than the first threshold to require an increased matching between the transmission characteristic of the unauthenticated wireless telephone and the stored fingerprint of the corresponding authorized wireless telephone; and

a processor connected to the fingerprint analyzer and the storage device, and operable to determine whether the designated destination is in the suspicious data or the locally invalid data for the corresponding authorized wireless telephone and to execute through the fingerprint analyzer a fingerprint analysis using the second threshold when the designated destination is determined to be in the suspicious data, the processor operable to classify the call as invalid when the designated destination is determined to be in the locally invalid data for the corresponding authorized wireless telephone regardless of whether the fingerprint analyzer identifies the unauthenticated wireless telephone as authorized.