Patent ID: 8140854

Claim:
A user verification method to verify a user when using a usage target system communicating with a verification server via a first communication channel the method comprising: registering a password derivation pattern based on at least one specific element selected from among an element group of elements displayed in a plurality of matrices, the element group constituting a predetermined pattern; receiving system identification information from an information terminal device of the user via a second communication channel, the system identification information being assigned to the usage target system and inputted to the information terminal device; wherein the usage target system includes a user interface to perform a mechanical or calculation process per an instruction provided via the user interface, and, in response to a user operation, display the system identification information, so as to enable the user to input the system identification information to the information terminal device, wherein the information terminal device is a portable communication device carried by a user such that the user of the information terminal device communicates with another portable communication device, generating a presentation pattern in which a predetermined character is assigned to the at least one specific element of the element group constituting the predetermined pattern upon receipt of the system identification information; sending the generated presentation pattern to the information terminal device via the second communication channel in order to cause the information terminal device to present a predetermined screen containing the generated presentation pattern and thereby allow the user to input the at least one character assigned to the at least one specific element corresponding to the password derivation pattern into the usage target system using the user interface thereof; receiving the inputted at least one character from the usage target system via the first communication channel; judging whether the usage target system is legitimate based on the system identification information received from the information terminal device, and judging whether the received at least one character is legitimate based on the generated presentation pattern and the user's password derivation pattern; and sending an authentication result of the judgment made to the usage target system that is judged legitimate via the first communication channel.