Electrical circuit testing device and method

A system for a user authentication and identity theft prevention using a one-time random key, comprising:

• a computer terminal comprising a processor configured to access, via a network, a service server, and request the user authentication in order to use a service that requires the user authentication through the service server;
• and
• a mobile terminal comprising a processor configured to
• receive, via the network, a user authentication message, which includes an authentication key,
• create an authentication-related value by performing a first Exclusive-OR (XOR) operation on the authentication key and a security key, wherein the security key comprises a plurality of one-time random keys including a selected one-time random key, wherein creating the authentication-related value uses one of a first set of plurality of pre-determined equations each of which distinctively performs the first Exclusive-OR (XOR) operation on the authentication key and the security key, and
• send, via the network, the authentication-related value;
• and
• a user authentication server comprising a processor configured to
• create the authentication key by performing a third Exclusive-OR (XOR) operation on a couple of selected one-time random keys, in response to a request for the user authentication,
• send, via the network, the user authentication message including the authentication key, to the mobile terminal,
• receive, via the network, the authentication-related value from the mobile terminal,
• create a verification key by performing a second XOR operation on the plurality of one-time random keys except the selected one-time random key, wherein creating the verification key uses one of a second set of plurality of pre-determined equations each of which distinctively performs the second XOR operation on the plurality of one-time random keys except the selected one-time random key, and the each of the second set of plurality of pre-determined equations distinctively corresponds to one of the first set of plurality of pre-determined equations, and
• perform the user authentication by verifying whether the verification key is identical to the authentication key
• wherein the computer terminal, the mobile terminal, and the user authentication server are separated hardware devices and connected with each other via the network, and the network includes at least one of a cellular network, a Wi-Fi network, a Wide Area Network (WAN), and a Local Area Network (LAN).