Abstract: A digital measurement apparatus measures a physical measurement object, provides a digital signature of public-key cryptography to measured data of a thus-measured physical quantity, and manages the measured data. The apparatus generates at least a pair of a public key and a private key, to be used for the digital signature of the public-key cryptography, through a key generating algorithm.

Abstract: An approach for storing and maintaining data is disclosed. One or more sensors are provided for detecting unauthorized access to a first non-volatile storage. If unauthorized access to the first non-volatile storage is detected, then the data on the first non-volatile storage is deleted by overwriting the data on the first non-volatile storage with a predetermined value so that the data cannot be recovered. The first non-volatile storage is registered with a registration authority to provide authentication of the data maintained on the first non-volatile storage.

Abstract: An electronic equipment has parts which may be subjected to maintenance and are specified by a maintenance range. The electronic equipment includes a setting part which is set with a predetermined maintenance range in which the maintenance is permitted, an authenticating part to authenticate validity of a maintenance-attending person for the electronic equipment, and a changing part to temporarily change the predetermined maintenance range set in the setting part, in response to a change instruction, when the authenticating part authenticates the validity of the maintenance-attending person.

Abstract: Identification information of a document is read from the document. At least one operation requirement is specified and selected according to a document profile related to the identification information by referring to a security policy describing a handling rule concerning the document. An operation with respect to the document is controlled according to the operation requirement.

Abstract: In a document protecting system, a distributor terminal implementing a document protecting program obtains an encryption key to encrypt a document file, associates a print request to the document file, and encrypts the document file by the encryption key. And a user terminal implementing a document printing program obtains a decryption key of document file being encrypted, decrypts the document file based on the obtained decryption key, obtains a print requirement associated with the document file, and executes a printing process so as to satisfy the print requirement.

Abstract: An approach for storing and maintaining data involves determining whether data has been stored on a first non-volatile storage for a specified period of time. If so, then the data on the first non-volatile storage is deleted by overwriting the data on the first non-volatile storage with a predetermined value so that the data cannot be recovered. The first non-volatile storage is registered with a registration authority to provide authentication of the data maintained on the first non-volatile storage. A duplicate copy of the data is stored on a second non-volatile storage and if a determination is made that the data has been stored on a first non-volatile storage for a specified period of time, then the duplicate copy of the data is deleted by overwriting the duplicate copy of the data on the second non-volatile storage with the predetermined value.

Abstract: An approach for storing and maintaining data involves determining whether a first non-volatile storage has failed or otherwise encountered a problem. If so, then the data on the first non-volatile storage is deleted by overwriting the data on the first non-volatile storage with a predetermined value so that the data cannot be recovered. The first non-volatile storage is registered with a registration authority to provide authentication of the data maintained on the first non-volatile storage. A duplicate copy of the data is stored on a second non-volatile storage and if a determination is made that the first non-volatile storage has experienced a problem, then the duplicate copy of the data on the second non-volatile storage becomes active.

Abstract: A method of certifying the existence of electronic information released on a network at a time and date. The network connects one or more computer servers and a plurality of client computers with each other. Electronic information of a web page stored in one of the plurality of client computers is accessed using information of its location from one of the computer servers based on a request from one of the client computers. A copy of the electronic information is then obtained. Attribute information is generated from the location, access time, and date when the electronic information is accessed. An electronic certificate may be generated by uniquely specifying the electronic information and the attribute information as inherent information identifying the electronic information. The copy of the electronic information is stored in a memory by tying up the electronic information with the electronic certificate and the attribute information.

Abstract: The reliability due to time-elapsing variation of the magneto-optic disk and the data recorded on the magneto-optic disk are evaluated. A magneto-optic disk driving apparatus can preserve a sheet of magneto-optic disk during the period over the endurable number of years, and a file manager can issue an alarm to the user in accordance with the deterioration state of the magneto-optic disk. The magneto-optic disk drive controlling apparatus for controlling the magneto-optic disk driving apparatus capable of taking in or taking out the magneto-optic disk by the operation of user's hands or the automatic transportation by use of the host computer comprises a disk deterioration judging (grasping) measure and a disk deterioration tolerance excess alarming measure.

Abstract: A computer system which prevents unauthorized access to files within a memory such as a disk. A first software program within the computer attempting to access the files is authorized to access the files whereas another software program within the computer is not authorized to access the files. When the first software program desires to access the files and uses the appropriate password or key-code, the first software program is allowed access to the information whereas the second software program within the same computer is not allowed access to the information within the files. The files may be stored in a file server which is networked to a client computer containing the software programs. Alternatively, the files may be stored in an intelligent peripheral device which is not located within a conventional file server and the computer connected to the peripheral device includes the software programs which attempt to access the files within the peripheral device.

Abstract: The reliability due to time-elapsing variation of the magneto-optic disk and the data recorded on the magneto-optic disk are evaluated. A magneto-optic disk driving apparatus can preserve a sheet of magneto-optic disk during the period over the endurable number of years, and a file manager can issue an alarm to the user in accordance with the deterioration state of the magneto-optic disk. The magneto-optic disk drive controlling apparatus for controlling the magneto-optic disk driving apparatus capable of taking in or taking out the magneto-optic disk by the operation of user's hands or the automatic transportation by use of the host computer comprises a disk deterioration judging (grasping) measure and a disk deterioration tolerance excess alarming measure.