Patent ID: 7035850

Claim:
An access control system comprising: a memory which stores necessary information for various processes; a processor for input/output to a file stored in a storage medium; a policy file in said memory in which access control policy for said file is described; an access controller which determines the validity of a request for access to said file according to said access control policy; a monitoring processor which monitors issuance of a file access request made by means of said input/output processor, notifies said access controller of an issued file access request and receives the result of validity determination from said access controller; and an exclusive controller which protects said memory's storage regions in use by said input/output controller, access controller and monitoring processor and shields said policy file from an access execution processor other than said input/output controller, access controller and monitoring processor, wherein: said policy file contains information as an access control policy to identify the access request source, access execution processor and access type for the file to be accessed; and said monitoring processor uses information to identify the access request source, access execution processor and access type to notify said access controller of said issued file access request.