Abstract: An access control apparatus comprises a control unit that, based on predetermined access control information, restricts access to an electronic file by software that is permitted to access or prohibited from accessing the electronic file. An access control system comprises: an access control apparatus that has a control unit that, based on predetermined access control information, restricts access to an electronic file by software that is permitted to access or prohibited from accessing the electronic file; and a management apparatus that is provided outside the access control apparatus, and provides, to the access control apparatus, at least one of the predetermined access control information and a judgment result based on the predetermined access control information.

Abstract: An access control apparatus is an access management system that manages access to an electronic file stored in a file sharing server and includes: a file access information receiving unit that receives, from a user device, file identification information identifying the electronic file to be accessed by the user device; a restriction information receiving unit that receives restriction information indicating a restriction imposed by the file sharing server on access, by the user device, to the electronic file that is identified by the file identification information received by the file access information receiving unit and is stored in the file sharing server; and an access control information transmitting unit that transmits, to the user device, access control information that is for controlling access to the electronic file in the user device and corresponds to the restriction information.

Abstract: A file encrypting apparatus includes: an encryption key acquiring unit that acquires one or more encryption keys determined for respective ones of one or more users permitted to access an electronic file; a file encrypting unit that encrypts the electronic file; a supplementary information encrypting unit that encrypts, by using the one or more encryption keys, supplementary information including a file decryption key required for decryption of the encrypted electronic file; and an output unit that outputs the encrypted supplementary information in association with the encrypted electronic file.

Abstract: An electronic file sending method is provided to securely and easily send en electronic file to a receiver. A receiving apparatus receives from a sending apparatus an electronic mail including an encrypted electronic file. The sending apparatus uses a public key of a management server to encrypt a decryption password that is necessary to decrypt the encrypted electronic file and sends the encrypted decryption password to the management server. In association with a file identifier of the electronic file, the management server stores the decryption password and an electronic mail address of a correct receiver, who is a receiver of the receiving apparatus. The receiving apparatus sends to the management server the file identifier of the electronic file and the electronic mail address of the receiver. The management server uses a public key of the receiving apparatus to encrypt the password and sends the encrypted password to the receiving apparatus.