A non-transitory, computer-readable recording medium having stored therein a program for causing a computer execute a process of transmitting a first random value by proximity radio communication to a device coupled via a server and a network, receiving data in which the first random value is encoded, from the device by the proximity radio communication, determining whether the first random value matches a value obtained by decoding the data with a server key obtained in advance from the server, when the value obtained by decoding the data matches the first random value, authenticating a user, and causing the information processing device to execute processing for transmitting a result of the authenticating the user to the server via the device.