Abstract: The digital signal recording/reproducing apparatus inputs a digital signal having a control flag as to a temporary copy permission, and records the digital signal temporarily into a recording medium in accordance with conditions in the control flag, then reproducing the digital signal temporarily from the recording medium in accordance with the conditions in the control flag. The recording/reproducing of the temporary copy is permitted, depending on the following conditions: The recording medium's type, the reproducing point-in-time, the reproducing time-period, and the reproducing frequency. With this method employed, even in a program permitting no recording, the temporary recording/reproducing is permitted under a condition of being limited to the time-shift recording on the receiving side.

Abstract: An authentication method for use in sending/receiving data between a coded data output apparatus for outputting coded data having a water mark, and a recording apparatus for recording data onto a recording medium, the method including: deciding a type of the recording medium used by the recording apparatus; based on a result of the deciding, selecting, from a plurality of authentication methods, an authentication method corresponding to the type of the recording medium, and conducting authentication between the coded data output apparatus and the recording apparatus, using the authentication method; sending/receiving data between the coded data output apparatus and the recording apparatus after conducting the authentication; and in a case where the coded data has the water mark, detecting the water mark by the coded data output apparatus, wherein the data exchanged between the coded data output apparatus and the recording apparatus is scrambled by a scrambling method corresponding to the type the recording me

Abstract: An authentication method for use in sending/receiving data between a coded data output apparatus for outputting coded data having a water mark, and a recording apparatus for recording data onto a recording medium, the method including: deciding a type of the recording medium used by the recording apparatus; based on a result of the deciding, selecting, from a plurality of authentication methods, an authentication method corresponding to the type of the recording medium, and conducting authentication between the coded data output apparatus and the recording apparatus, using the authentication method; sending/receiving data between the coded data output apparatus and the recording apparatus after conducting the authentication; and in a case where the coded data has the water mark, detecting the water mark by the coded data output apparatus, wherein the data exchanged between the coded data output apparatus and the recording apparatus is scrambled by a scrambling method corresponding to the type the recording me

Abstract: A system effecting a data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a descrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.

Abstract: A system effecting a data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a descrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.

Abstract: A data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a scrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.

Abstract: A method and a device for managing a computer network, especially a technique for ensuring the security of a network. A computer network system in which computers are connected to each other through transmission lines, each computer stores the data which constitutes a moving type software exclusively used for security and transmitted together with a message when the computer transmits the message to another computer of the system, and executes the moving type software by using the stored data upon receiving a message from another computer.

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: 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: 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: A technology of digital watermarking for binary images (including documents) is provided, which is capable of adjusting the amount of information to be embedded while avoiding the deterioration of image quality as far as possible. The watermark information is inserted by giving the standard for judgment of modification and the order of preference for modification according to the characteristic properties of the human visual sense for binary images and performing modification on pixels sequentially in the descending order of preference.

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: The invention provides a method for verification having a structure that reflects reliability of a signature history properly for a hysteresis signature used for verification based on the signature history, and provides a method for arbitration and an arbitrator apparatus that solve a dispute on correctness of a signature based on the method for verification. Furthermore, the invention provides a method for managing history that mitigates the signature history management burden on a signer. Reliability is set on a signature forming 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 invention provides a method for verification having a structure 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.

Abstract: A reproducing method and apparatus for receiving and reproducing data and outputting the data into an external device. After reproducing the data, a descrambler corresponding to a type of the reproduced data is selected from a plurality of descramblers and the external device is authenticated by a selected authenticator which is included in a plurality of authenticators for authenticating the external device and corresponds to the selected descrambler, and the data is outputted.

Abstract: A data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a scrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.

Abstract: In a data transmission method for information data containing additional information data therewith, comprising, at a transmitter side, following steps: adding error correction codes for correcting error to said additional information data; embedding said additional information data added with said error correction codes into the information data by plural times, repetitively; and transmitting the information data embedded with the repetitive additional information data therein, and comprising, at a receiver side, following steps: receiving the transmitted information data embedded with the repetitive additional information data therein; detecting the repetitive additional information data embedded from said transmitted information data received; determining said additional information data on a basis of a majority rule when receiving said information data; and correcting error with using the error correction codes received and determined when said additional information data contains error(s) therein.

Abstract: The present invention can detect watermark information from motion picture of various scanning methods and various picture sizes without causing increase of a memory capacity. A watermark information detection apparatus 1 converts encoded watermarked motion picture 4 into standard motion picture 5 having the smallest data size among the assumed kinds of motion picture. Further, the watermark information detection apparatus 1 scales a standard coordination system that is utilized for specifying embedding locations of a watermark pattern. Then, with respect to each field of the standard motion picture 5, watermark information is detected from predetermined locations specified in the scaled standard coordinate system by the watermark pattern.

Abstract: A method for using digital contents is provided. In the method, a request is made to a provider apparatus for a certificate containing a first provider ID embedded therein by a certification authority, and the certificate is received from the provider apparatus. A decision is made by using the certificate as to whether or not the provider is authorized by the certification authority. A request is made to the provider apparatus for a digital content having a second provider ID embedded therein by a contents guarantee authority when the provider is authorized by the certification authority, and the digital content is received from the provider. The first provider ID is read from the certificate, the digital content is correlated with the second provider ID, and the digital content is stored in a storage medium. The second provider ID is detected from the digital content in response to a request to use the digital content.

Abstract: In a data transmission method for information data containing additional information data therewith, comprising, at a transmitter side, following steps: adding error correction codes for correcting error to said additional information data; embedding said additional information data added with said error correction codes into the information data by plural times, repetitively; and transmitting the information data embedded with the repetitive additional information data therein, and comprising, at a receiver side, following steps: receiving the transmitted information data embedded with the repetitive additional information data therein; detecting the repetitive additional information data embedded from said transmitted information data received; determining said additional information data on a basis of a majority rule when receiving said information data; and correcting error with using the error correction codes received and determined when said additional information data contains error(s) therein.

Abstract: 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.