A communication terminal communicable with first and second servers (105; 106) through a network, characterized in that there are provided: an operating system configured to control the host controller by calling one of a plurality of interfaces, including a certain interface that controls a sensor; a browser that, if the operating system is restricted from adding a device driver, making an inter-process communication amongst applications of the communication terminal, or expanding the browser by a plug-in, is configured to start a child process using, as an argument, an inter-process communication received from another application; a host controller; and an authentication-management-application configured to exchange data with the sensor that is coupled to the host controller through the certain interface of the operating system, and performs a process including requesting a user authentication by transmitting to the second server a user ID and matching data detected by the sensor, and acquiring a password transmitted from the second server in a case in which the user authentication is successful; replaying, between the first server and the second server, authentication data transmitted from the first server in response to requesting the first server to provide a service; first transmitting a user ID that is prepared in advance and the acquired password to the second server, in a case in which a screen that urges the user ID and the password to be input is received from the second server; and disconnecting a communication with the second server without redirecting an authentication response that includes information specifying the first server and is transmitted from the second server in a case in which a pair of the user ID and the password transmitted to the second server is stored in the second server and authentication is successful, and starting the child process of the browser by the argument based on the authentication response and transmitting the authentication response to the first server, in order to make a log-in to and receive the service from the first server. an operating system configured to control the host controller by calling one of a plurality of interfaces, including a certain interface that controls a sensor; a browser that, if the operating system is restricted from adding a device driver, making an inter-process communication amongst applications of the communication terminal, or expanding the browser by a plug-in, is configured to start a child process using, as an argument, an inter-process communication received from another application; a host controller; and an authentication-management-application configured to exchange data with the sensor that is coupled to the host controller through the certain interface of the operating system, and performs a process including requesting a user authentication by transmitting to the second server a user ID and matching data detected by the sensor, and acquiring a password transmitted from the second server in a case in which the user authentication is successful; replaying, between the first server and the second server, authentication data transmitted from the first server in response to requesting the first server to provide a service; first transmitting a user ID that is prepared in advance and the acquired password to the second server, in a case in which a screen that urges the user ID and the password to be input is received from the second server; and disconnecting a communication with the second server without redirecting an authentication response that includes information specifying the first server and is transmitted from the second server in a case in which a pair of the user ID and the password transmitted to the second server is stored in the second server and authentication is successful, and starting the child process of the browser by the argument based on the authentication response and transmitting the authentication response to the first server, in order to make a log-in to and receive the service from the first server. requesting a user authentication by transmitting to the second server a user ID and matching data detected by the sensor, and acquiring a password transmitted from the second server in a case in which the user authentication is successful; replaying, between the first server and the second server, authentication data transmitted from the first server in response to requesting the first server to provide a service; first transmitting a user ID that is prepared in advance and the acquired password to the second server, in a case in which a screen that urges the user ID and the password to be input is received from the second server; and disconnecting a communication with the second server without redirecting an authentication response that includes information specifying the first server and is transmitted from the second server in a case in which a pair of the user ID and the password transmitted to the second server is stored in the second server and authentication is successful, and starting the child process of the browser by the argument based on the authentication response and transmitting the authentication response to the first server, in order to make a log-in to and receive the service from the first server.