Patent ID: 8638231

Claim:
An authentication apparatus, comprising: a memory that stores authentication information representing a check target; and a processor that executes a program including: first authenticating the check target at an entrance of the check target to a first area; tracking the check target in the first area; second authenticating the check target at an entrance of the check target to a second area after being authenticated by the first authenticating; and detecting a check target present in a detection area and expected to be authenticated by the second authenticating, wherein the second authenticating retrieves, from the memory, registration information of the check target detected by the detecting and authenticates the check target authenticated by the first authenticating using the registration information, wherein the detecting detects, in accordance with tracking information from the tracking, that the check target has gotten close to or in physical contact with another check target, and wherein the second authenticating retrieves, from the memory, registration information of the other check target that the check target has gotten close to or in physical contact with, together with the registration information of the detected check target, and authenticates the check target using the retrieved registration information.