Abstract: A system for managing a digital content, particularly a digital content to which a copyright is claimed, and a system for supplying a public-key which is used in the management of the digital content are provided. The digital content management program is embedded to an operating system of a user apparatus as a micro kernel, a watch program or a watch command which is linked to the digital content management program is transmitted to the user apparatus by using a network or data broadcasting, and thereby, the illegitimate usage of the digital content is watched. A visible watermark is added to the digital content when illegitimately utilized, to restrain later usage. Even in regular usage, the route of copying or transferring the digital content can also be ascertained by adding an invisible watermark. Further, a public-key is put in a public-key distribution screen to be distributed by the network or broadcasting.

Abstract: A threaded joint with trapezoidal threads for oil well pipes superior in sealing performance: having a load flank angle &thgr;1 of each thread satisfying desired conditions; having a shape of the thread such that opposite flanks of the trapezoidal thread come into contact with flanks of a corresponding thread simultaneously when the joint is so fastened as to give a threaded portion of the joint an interference &Dgr;d of not smaller than 0.12% and not larger than 0.8% of the outer diameter of a pipe to be jointed; having a gap formed between a crest and a bottom of this trapezoidal thread and set to be not larger than 0.2 mm; and having dimensional tolerances of thread width and thread height of the threads satisfying desired conditions.

Abstract: Techniques for secure distribution of digital representations that combine encryption and watermarking. When a user at a client desires to download a digital representation, the user makes a request to a server for the digital representation, which encrypts the digital representation using a first key and downloads the encrypted digital representation to the user. Before the user performs any operation on the decrypted digital representation, a secret fingerprint watermark identifying the user is added to the digital representation. The fingerprint watermark is added either at the server or at the client and a copy of the fingerprinted digital representation is kept at the server. If the user makes an impermissible use of the digital representation, the secret fingerprint watermark can be used to identify the user. The request made by the user indicates the type of use that the user wished to make of the digital representation.

Abstract: An automotive battery plug (1), once fitted in a cigar lighter socket (111), is retained therein with proper retentive force. When it is pulled out of the socket, the retentive force decreases, allowing ease in the removal of the plug (1). A slider (25, 31) slidable in a plug housing (2) has on its either side surface a support portion (25a) and an inclined portion (25b) forming a slope (26) contiguous to the support portion (25a). When a return end portion (17b) of each leaf-spring contact piece (17) abuts with the support portion (25a) of the slider (25), a contact portion (17a) of the contact piece (17) greatly protrudes from the periphery of the plug housing (2) through an opening (19), permitting the battery plug (1) to be fitted and held in the cigar lighter socket (111) with suitable retentive force.

Abstract: A liquid container having a stable shape that is easy to fill and that enables the user to pour out liquid to the last drop into an intended target using one hand only and without spilling the liquid. An internal space of a container is defined by a front surface portion, a rear surface portion having the shape identical with the front surface portion, and a pair of gussets each connecting together each confronting edges of the front and rear surface portions. The gusset has a folded arrangement. If liquid is filled in the container, V-shape of the gusset expands to provide a three dimensional container. The gussets extend to a neck portion. By the expansion of the gussets, a spout has a sufficient open area capable of controlled pouring of the liquid therethrough. If the liquid amount in the container is reduced, the spout is automatically closed when the container is self-standing on a table.

Abstract: A data copyright management apparatus for handling data copyrights and data of digital cash, and for use in video conference systems is provided. The data copyright management apparatus is connected to a user terminal, and is used for performing decryption of encrypted digital data to be copied and edited, and also performing encryption of decrypted digital data to be stored, copied and transferred. The data copyright management apparatus may comprise one central processing unit so that either one of a microprosser of the user terminal and the microprocessor of the data copyright management apparatus performs decryption of the encrypted data and the other performs re-encryption of decrypted data at the same time. The data copyright management apparatus may also comprise two central processing units so that one central processing unit performs decryption of the encrypted data and the other central processing unit performs re-encryption of the decrypted data at the same time.

Abstract: A crypt key system for decrypting encrypted data for use, by a permit key including a decryption key, comprising a database/charging center, a broadcasting station, a receiving device and a communication device. The permit key is supplied to the broadcasting station in advance from the database/charging center. The permit key is broadcast from the broadcasting station. The receiving device receives the permit key via the broadcast. A request for use is executed to the database/charging center via the communication device. The database/charging center transmits the encrypted data via a communication line to the communication device and charges a fee. The communication device decrypts the encrypted data with the permit key received by the receiving device.

Abstract: The present invention provides a process for managing data copyright in the case when a primary user produces new data by editing a plurality of original data which have been supplied from data broadcasting, a recording medium or a database, and supplies the new data to a secondary user. A public-key and a private-key of the primary user, and a first secret-key and a second secret-key of the original data, each of which is controlled by a copyright management center, and an edit program are used. The primary user, who is supplied a plurality of original data encrypted by each first secret-key thereof, decrypts the plurality of original data by each of the secret-keys and produces new data using the edit program. The primary user re-encrypts the new data by the second secret-key of each original data, respectively. The re-encrypted data is supplied to the secondary-user, together with editing process data which includes a digital signature generated using the private-key.

Abstract: A data copyright management system is provided, in which a primary user edits a received data and supplies the edited data to a secondary user. The copyright management system comprises a database and a key control center, and uses a primary copyright label, a primary use permit key including a first crypt key, a secondary use permit key, a third crypt key, and a copyright management program. The primary user decrypts the copyrighted primary data, which is encrypted using the first crypt key and supplied, to plaintext using a primary use permit key obtained from the key control center and utilizes it. If the copyrighted primary data is stored in a primary user device, it is re-encrypted using the primary use permit key. The primary user receives a secondary use permit key for editing the copyrighted primary data from the key control center and edits the copyrighted primary data. The data being edited is encrypted using the secondary use permit key and is stored.

Abstract: A system for dealing in an original data content and an edited data content. A data content is handled as an object, and the data content is edited by editing a data content, functioning as an object, in accordance with an edit program. The edited data content is expressed by the original data content and the editing scenario which describes editing detail by the edit program. Only the encrypted editing scenario is dealt in. Upon receipt of the encrypted editing scenario, a user decrypts the encrypted editing scenario using a crypt key obtained from a key management center, and obtains the original data content from the database in accordance with the editing scenario and re-constitutes the edited data content. In case there is the one who wishes sale of the editing scenario, its utilization right is sold by auction.

Abstract: An apparatus and method of producing iron carbide of predetermined quality is disclosed. The method of producing iron carbide (Fe.sub.3 C) comprises reducing and carburizing an iron-containing raw material containing iron oxides (e.g., hematite) or iron hydroxides as main components, wherein the raw material is partially reduced to a reduction ratio of 50 to 65% by a gas containing mainly hydrogen in a first stage of the reaction process, then the partially reduced raw material is further reduced and carburized with a gas containing mainly hydrogen and methane in a second stage of the reaction process to provide iron carbide.

Abstract: A data copyright management system comprises a database for storing original data, a key control center for managing crypt keys, copyright management center for managing data copyrights, and a communication network for connecting these sections. Data supplied from the database to users is encrypted and distributed. The users decrypts the encrypted data by crypt keys obtained from the key control center or copyright management center. To supply data to users, there are the following two methods: a one-way supplying of encrypted data to users by means of broadcasting or the like; and two-way supplying of encrypted data to users corresponding to users' requests. A crypt key system used for encrypting data uses a secret-key cryptosystem, a public-key cryptosystem or a cryptosystem combining a secret-key and a public-key and further uses a copyright control program to control data copyrights.

Abstract: To prevent piracy or leakage of data content, a cryptography technique and electronic watermark technique are combined together and used. In a data content supplied to a user, a user data is entered as electronic watermark by a data management center, and the data content with an electronic watermark entered in it is encrypted using a crypt key and is supplied. The encrypted data content is decrypted using a crypt key distributed from the data management center and is used. In case it is to be stored, it is encrypted using another crypt key. In case the data content is copied and transferred to other user, a user data of the other user is entered as electronic watermark, and a scenario to enter the user data of the other user as electronic watermark is registered at the data management center, and the data content with electronic watermark entered in it is encrypted using another crypt key and is supplied.

Abstract: The present invention provides a system to ensure security of data in a computer network system. A center certifies a public-key of user of the system and distributes a secret-key. A first system comprises the center in a network, an information provider and a plurality of users. The center identifies utilization status by requests of the secret-key. The data is encrypted by the secret-key and is stored and transferred, while the data to be stored and transferred is encrypted by a secret-key different from the secret-key of the transferred data. An original data label is added to the original data, and an edit label is added to the edited data, and the center does not store the data and stores only the original data label and the edit label. A second system comprises a center and an information provider in a network, and a plurality of users utilizing the network. The center stores the original data and editing scenario, and also the original data label, user label and edit label.

Abstract: Powdered ore is fed into fluidized bed reactor 1 after preheating by hot blast in preheating furnace 2. Iron oxide particles are recovered from an exhaust gas of the preheating furnace 2 by dust catcher 3, and the iron oxide particles are reduced to iron in reducing furnace 4. The reduced iron particles are added into the flow path of fluidized bed reactor 1 to catalyze the reaction producing iron carbide.

Abstract: In order to obtain a crop which provides an increased storage lipid content in its seed, the activity of cytosolic pyruvate kinase of a seed is substantially lowered as compared with the endogenous activity of pyruvate kinase in the plant seed. Preferably, the activity of phosphoenolpyruvate carboxylase is substantially lowered as compared with the endogenous activity of phosphoenolpyruvate carboxylase in the seed. Thus the storage lipid content in the plant seed is increased.

Abstract: A system for the so-called "pay-per-program" is provided for viewing individual program on pay basis without signing a comprehensive contract. In response to a request for viewing a pay program executed via public telephone line from an applicant for viewing, a charging center sends a viewing permit code for viewing a pay program to a data communication device and collects a fee for the pay program. Upon receipt of the viewing permit code, a receiving device offers the pay program according to the viewing permit code. The broadcasting program is scrambled by three modes of fixed, selective and change. The request for viewing is executed in three modes by specifying time, program number and temporary number. As the viewing permit code, one of three modes is adopted: decode data, non-opened program number or decode data number.

Abstract: A data copyright management apparatus for handling data copyrights, and data of digital cash and video conference system is provided. The data copyright management apparatus comprises a CPU, ROM, EEPROM, and RAM. The ROM, EEPROM, and RAM are connected to the CPU bus, and a system bus of a device which utilizes the data can be connected to the CPU bus. A data copyright management system program, crypt algorithm, and user information are stored in the ROM, and a first public-key, a first private-key, a second public-key, a second private-key, a first secret-key, a second secret-key, and copyright information are stored in the EEPROM. The data copyright management apparatus may be configured in the form of a monolithic or hybrid IC, a thin IC card, PC card, insertion board, and further, may be incorporated in a computer, television set, set-top box, digital video tape recorder, digital video disk recorder, digital audio tape apparatus, or personal digital assistants, and the like.

Abstract: A novel gene that can be used to identify male-sterile cytoplasm in plants, for example, of the Cruciferae family, and a method for producing hybrid plants using this gene are provided. This novel cms cytoplasmic gene is valuable in that it can be utilized in the production of hybrid plant seeds. This invention is also useful for rapidly identifying Kosena cms cytoplasm, a novel cytoplasm which exhibits characteristics valuable in plant breeding. In addition, this gene may possibly be used to confer cms onto a broad range of plant species, not limited to those of the Cruciferae family, by its introduction into nuclear or mitochondrial genomes.

Abstract: A data copyright management system is provided, in which a primary user edits a received data and supplies the edited data to a secondary user. The copyright management system comprises a database and a key control center, and uses a primary copyright label, a primary use permit key including a first crypt key, a secondary use permit key, a third crypt key, and a copyright management program. The primary user decrypts the copyrighted primary data, which is encrypted using the first crypt key and supplied, to plaintext using a primary use permit key obtained from the key control center and utilizes it. If the copyrighted primary data is stored in a primary user device, it is re-encrypted using the primary use permit key. The primary user receives a secondary use permit key for editing the copyrighted primary data from the key control center and edits the copyrighted primary data. The data being edited is encrypted using the secondary use permit key and is stored.