Apparatus and method for preventing fraudulent calls in a wireless

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.