Abstract: An electronic document authenticity assurance technique and an information disclosure system both of which can compatibly realize the assurance of the authenticity of disclosure documents and the deletion of information inappropriate for disclosure. An electronic document is divided into constituent elements and an electronic signature is affixed to an arbitrary subset of a set including all the constituent elements. Otherwise, an electronic signature is affixed to data obtained by binding each of the constituent elements to information specifying the relationship between a respective one of the constituent elements and the structure of the electronic document. Otherwise, the hash values of the respective constituent elements are calculated and an electronic signature is affixed to data obtained by binding the calculated hash values together.

Abstract: In a signature generating method where not necessarily all of a plurality of signature generating devices work together each time to generate signatures, the present invention seeks to correctly and securely reflect data relating to previous signatures. When generating signatures, the data used for the next signature is sent beforehand to the other signature generating devices. Also, when generating signatures, at least one of the devices is used consecutively, thus allowing history data to be shared during signature generation.

Abstract: A publication system effective and secure to the publication agency and the user is provided for the publication agency, and a signature verifying function using the disclosed signature log entries is provided for the user. The publication agency discloses the signature log entries received from the users on Web, and acquires time-stamp at the time of the publication, and transmits them together with the publication notice back to the users. The publication agency also has the signature log, and either discloses part of the log at regular intervals in the newspaper or the like, or produces publication-purpose data on the basis of the signature log entries received from each user and discloses in the newspaper. The publication agency, after the newspaper publication, transmits the signature log of the publication agency to the users.

Abstract: A method for signature verification having a structure that reflects reliability of a signature history properly for a hysteresis signature used for verification based on the signature history. A method for arbitration and an arbitrator apparatus solve a dispute on correctness of a signature based on the method for verification. Furthermore, a method for managing history to migrate the management burden on a signer. Reliability is set on a signature issuing record that is a component of a signature history, reliability of the signature history is calculated based on the set reliability, and the calculated reliability is output as reliability of a verification result. The disclosure also provides a method for verification that reflects the reliability of a signature history properly and a method for arbitration and an arbitrator apparatus that solve a dispute on correctness of a signature. Furthermore, a signature history storage service apparatus mitigates the signature history storage burden on a signer.

Abstract: Data protection techniques for preventing deletion, alteration, and leakage of data due to carelessness of a user and other programs (including a computer virus) and for preventing alteration of a program that uses the data are provided using a multi-OS control program, a host OS directly used by the user and a guest OS for managing files to be protected are run. A communication control program determines whether access from a signature request program can be performed or not, based on an access control list. In the case of access being authorized, a signature generation program is executed. The signature generation program generates a signature using a private-key. The communication control program sends back the generated signature to a requesting source through an inter-OS communication program.

Abstract: A time stamp generating system has a time distribution server for generating time data depending on time and a user PC for holding time certification objective digital data. The time distribution server generates time data corresponding to a time point and distributes the time data. The user PC calculates time stamp generating data by using the time certification objective data as an input, acquires the time data generated by the time distribution server, and processes the time data on the basis of the time stamp generating data to obtain a time stamp.

Abstract: A reliably safe storage system is provided which makes provable the status of a file stored in a storage server at a time specified by a user and creates evidence information that will be effective in future. In response to a file status fixing request from the user over a network, a storage server generates file fixing guarantee data, including data publicized by a publication server, and saves the generated data with the file associated with the generated data.

Abstract: A method of managing digital signature includes the steps of preparing a signature log file storing signature log entry information, generating a new digital signature for a transmission message by reflecting, in the new digital signature, signature log entry information registered to the signature log file in the past; generating signature log entry information associated with the new digital signature and registering the signature log entry information to the signature log file; and preparing a user search file in addition to the signature log file; registering, to the user search file, user identifier information indicating a transmission destination of the transmitted digital signature and a transmission source of the received digital signature, with a correspondence established between the information, the user identifier information, and each signature log entry information in the signature log file.

Abstract: A network system capable of preventing the leakage of a confidential file by an inadvertent act of a transmitting party and capable of meeting the requirement for an arbitrary file format is disclosed. A label indicating a security level (“confidential” or “unclassified”) is attached to the file in a client terminal, which transmits the labeled file outside. A transmission management program on a gateway server checks the label of the file, and in the case where the security level is “unclassified”, transmits the file to an external network. Also, a label management program manages the labeled file in the client terminal.

Abstract: A defect detector having: a first optical system including a first light source to irradiate a surface of a subject with coaxial incident-light while scanning, and a first imaging device to receive light regularly reflected from the subject and change the light to a first electrical signal to form a first electrical image; a second optical system including a second light source to irradiate the surface of the subject with inclined light while scanning, and a second imaging device to receive light scattered at the subject and change the light to a second electrical signal to form a second electrical image, in which the inclined light of the second light source does not meet the coaxial incident-light of the first light source; and a computer to compare the first electrical signal with a predetermined first threshold to detect a concavo-convex defect on the surface of the subject, and to compare the second electrical signal with a predetermined second threshold to detect a blocky color defect on the surface of

Abstract: A contents control method for controlling a process on the receiving side which is applied to contents transmitted from the transmitting side to the receiving side, includes a step of adding, when a predetermined block of the transmitted contents is an area where control information for controlling the process substance on the receiving side which is applied to the contents is added, the control information to the block. The method also includes a step of receiving a process designation concerning the transmitted contents, and a step of applying, when user information stored in a receiving side apparatus which receives the transmitted contents, or information concerning the receiving side apparatus satisfies conditions corresponding to the received process designation in the control information added to the block of the contents, a process corresponding to the process designation to the received block.

Abstract: Techniques of improving the safety of an information processing system at low cost are provided, the information processing system having an OS provided with an access control function based upon discretionary access control for preventing illegal accesses to files. A method and apparatus for providing the information processing system with functions and areas usable only by a specific user different from a system administrator. The areas are provided with an access control function in order to prevent the access control function from being tampered.

Abstract: In a signature generating method where not necessarily all of a plurality of signature generating devices work together each time to generate signatures, the present invention seeks to correctly and securely reflect data relating to previous signatures.

Abstract: According to the present invention, techniques, including a method and system, for restoring and/or validating data and/or associated signature log entries are provided. One embodiment of the present invention provides a method for validating a restored message, having an entry generated in a signature log for a message, where the entry includes cryptographic information associated with the message; Next, when said message is lost, the restored message is generated responsive to a request; and the restored message is validated using the signature log. In another embodiment a method for validating a selected log entry by using a signature log having a plurality of recorded log entries is provided. The method includes: computing a cryptographic value for the selected log entry; and determining if the cryptographic value is part of another recorded log entry.

Abstract: The present invention provides a symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection.

Abstract: The present invention provides a symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection.