Patent ID: 7633375

Claim:
An information security system comprising: a portable information processing device; and a server, wherein the portable information processing device includes: an identification information detection/notification unit to detect detectable identification information of identification information of the portable information processing device, identification information of a user and identification information of a place, and to notify a server of the detected information; and a file using control unit to make an inquiry of the server if a file is a security target file when a user specifies an arbitrary file, and to control use of the specified file according to a response to the inquiry; and the server includes: a first storage unit to store, in advance, a using qualification in connection with each specific combination of the three types of identification information; a second storage unit to store, in advance, a level for each file; a using qualification determination unit to provide the using qualification corresponding to a specific combination stored in the first storage unit to the portable information processing device, if each piece of the notified identification information coincides with the specific combination; and a using permit determination unit to determine whether to permit use of the specified file by computing a level of the specified file referring to the second storage unit when there is the inquiry and comparing the level with the using qualification given to the portable information processing device, and to reply to the file using control unit, wherein the portable information processing device further includes a timer to monitor a time interval, and the identification information detection/notification unit checks a using condition of the portable information processing device that represents a user and a using place of the portable information processing device by detecting most recent identification information of the portable information processing device, identification information of the user and identification information of the using place at the time interval, and notifies the server of the most recent detected identification information if the using condition changes; and the using permit determination unit determines a new using qualification according to a change of the using condition based on the most recent identification information and notifies the portable information processing device of the new using qualification if the using qualification changes.