Patent ID: 8347368

Claim:
A user validation apparatus comprising: an extraction device which extracts user-agent information set by default in an HTTP header of a packet received from a terminal device, and extracts an access source IP address from the packet, by applying HTTP as a protocol of an application layer and IP as a protocol of an Internet layer; an information management device which stores the access source IP address and the user-agent information extracted by the extraction device from the packet received from the terminal device, which is operated by an individual user, in a storage device so as to correspond to user identification information of the individual user; and a determination device which determines whether or not a user operating a given terminal device is a valid user by verifying the access source IP address and user-agent information extracted by the extraction device from the packet received from the given terminal device against the access source IP address and user-agent information which are stored in the storage device so as to correspond to user identification information of the user operating the given terminal device, and by determining whether or not the access source IP address and the user-agent information extracted from the packet received from the given terminal device correspond to the access source IP address and the user-agent information which are stored in the storage device, wherein for the access source IP address extracted from the received packet, the determination device determines whether or not the access source IP address extracted from the received packet corresponds to the access source IP address stored in the storage device by determining whether or not a coincidence ratio of a predetermined bit unit to the access source IP address stored in the storage device is equal to or higher than a threshold and, for the user-agent information extracted from the received packet, the determination device determines whether or not the user-agent information extracted from the received packet corresponds to the user-agent information stored in the storage device by determining whether or not the user-agent information extracted from the received packet is identical to the user-agent information stored in the storage device, and when a plurality of sets of the access source IP address and the user-agent information are stored in the storage device so as to correspond to the user identification information of the user operating the given terminal device, the determination device determines that the user operating the given terminal device is a conditionally valid user if the determination device determines that only one of the access source IP address and the user-agent information extracted from the received packet corresponds to at least two sets of the access source IP addresses or the user-agent information among the plurality of sets stored in the storage device.