Hitachi, Ltd.

Takeshi Matsuki

Kazuo Takaragi

Hiroshi Yoshiura

Kunihiko Miyazaki

Ryoichi Sasaki

Seiichi Susaki

Hisashi Toyoshima

Hideo Noyama

Tsutomu Matsumoto

Mitsuru Iwamura

Hirokazu Aoshima

Koichi Maruyama

Toshiaki Arai

Kazuaki Tanaka

Masato Arai

Hirofumi Inomata

Yasuhiro Fujii

Kuniharu Osakabe

Shinji Itoh

Shuji Terada

Yoshiyasu Takahashi

Hisanori Mishima

Kunihito Takeuchi

Sakae Kunitoh

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.

Method and system for recovering the validity of cryptographically signed digital data

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. Otherwise, random numbers generated for the respective constituent elements are bound together, then the hash values of the respective random-numbered constituent elements are calculated, and then an electronic signature is affixed to data obtained by binding the calculated hash values together.

Electronic document authenticity assurance method and electronic document disclosure system

It has been impossible to suppress the copy of tickets which are printed on ordinary paper sheets. A client is provided with: a print control unit which prints a designated number of tickets. The acceptance server is provided with: a printed state verification unit which verifies the truth of the information on the state of printed matters; and a management unit which manages the type of a printer. Moreover, an issue server is provided with: a printing test data generating unit; a ticket generating unit which generates ticket data on the basis of the type of the printer; and a license data issuing unit which issues license data so as to instruct the number of ticket.

Print management system

A method for managing genuine characteristics of both an electronic document and a print medium comprising: a step for recognizing image data contained in the electronic document; a step for applying an extraction condition of an image feature previously determined and must be considered to the recognized image data to calculate a coordinate set corresponding to a pixel or a set of pixels, constituting the image feature; a step for recognizing at least a coordinate value among coordinate values and pixel color values, corresponding to each of coordinates constituting the coordinate set, and for embedding the recognized coordinate value as a code of a digital watermark into the pixel or the pixel set, constituting the image feature, or into an area in the vicinity; and a step for outputting the electronic document where the digital watermark embedding process operation has been carried out to the print medium.

Electronic document, genuineness management method for print medium thereof, genuineness management system, program, and program recording medium

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.

Trusted computer system

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.

Time stamp generating system

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.

The problem is to make a reliability decision on printed matter without using special ink or a dedicated blank. At least a part of a feature of a state included in printed matter is recorded by using a predetermined method at the time of printing. At the time of verification, the feature of the state acquired from the printed matter is compared with the feature recorded at the time of printing to conduct verification. As this feature, a feature value determined on the basis of a feature of the state of the printed matter, in the state of the printed matter determined in association with spatial distribution of a coloring portion on the printing surface, at the time when printing first information to be recorded is used.

Printed matter reliability decision method

Digital signature generating method and digital signature verifying method

A method and system is provided for automatically trading of items such as stocks with improved security. After receiving an initial identifying contact from a contractor, a trader will contact the contractor with a different communication device from the initial contact with confirmation information that was stored in association with a contractor first identifying code. The contractor must then reconfirm the fairness of the trading data using at least a portion of the confirmation information.

Automatic trading method and apparatus

An in-line stripe type color picture tube comprises an inner magnetic shield member having sufficient shield effect against both individual vertical and horizontal components of the earth magnetism and composite components as well. The inner magnetic shield member prevents unwanted shifts of electron beams to ensure that the positional relationship between a fluorescent screen and landing electron beams may have sufficient tolerances and color blur on the fluorescent screen may be prevented.

Growing community of inventors

Musashino, Japan

Takeshi Matsuki