Patent ID: 8272033

Claim:
A user authentication system, comprising: at least one computer for detecting and controlling potentially fraudulent login behavior by executing steps including recording both successful and unsuccessful login attempts, until a predetermined number of login attempts have been recorded, computing a time span over which the predetermined number of login attempts were made, detecting, responsive to the recorded login attempts, a pattern of login attempt results, wherein the detecting of the pattern of login attempt results includes generating a calibration factor based on the time span over which the predetermined number of login attempts were made and applying the calibration factor to the pattern of login attempt results, determining whether or not the pattern of login in attempt results has an indicator of at least one abnormal pattern range, and performing at least one action responsive to determining that the pattern of login attempt results has an indicator of at least one abnormal pattern range, including adjusting a threshold value of the at least one abnormal pattern range for a subsequent pattern of login attempt results.