Patent ID: 8862514

Claim:
A fingerprinting method to identify a user computer from other computers for an online transaction with an electronic commerce business comprising the steps of: creating, with aid of a processor, a first computer identifier in the course of a first online transaction with the electronic commerce business, and a second computer identifier in the course of a second online transaction with the electronic commerce business, wherein the first computer identifier identifies the user computer, wherein each computer identifier includes a delta of time parameter defined during the course of the online transaction by a time difference measured between a first clock measurement equal to a user computer local time and a second clock measurement equal to an electronic commerce business local time over a selected time interval; flagging the first computer identifier in response to determining the first online transaction may be a fraudulent transaction; comparing, with aid of the processor, the first computer identifier and the second computer identifier; determining, with aid of the processor, that a measured difference between the delta of time parameter of the first computer identifier and the delta of time parameter of the second computer identifier falls within a selected range; and indicating, to the electronic commerce business, that the user computer was used in the first online transaction and the second online transaction, based at least on the determination that the measured difference falls within the selected range.