Abstract: A file protection system for protecting a file which is stored in a storage unit includes a storage position deciding unit for deciding a positional-information corresponding to an area in which information of the file is stored in the storage unit and an encryption unit for encrypting the information of the file in accordance with a predetermined algorithm using at least a part of the positional-information decided by the storage position deciding unit. Information obtained by the encryption unit is stored in the area identified by the positional-information in the storage unit. A file protection system is operable when information of a file which was encrypted as described above is read out from a storage unit.

Abstract: The present invention was made in order to provide a technology capable of safely ciphering compressed and encoded image data irrespective of lines or media and carrying out a correct decoding operation without any shifts in the frames of ciphered moving pictures.Further, so as to prevent giving any means of encoding from comparison of image ciphered data and so as to generate totally different ciphered image data from the same data compressed images, a processing is executed not on an ECB mode but on such modes as CBC, CFB, OFB or the like. Moreover, as an initial vector, information different for frames included in a header, that is, time information from the start of an image or a frame sequential number, is used. In this way, even if compressed images within adjacent frames are accidentally the same, totally different ciphered data can be obtained.

Abstract: The present invention provides a data content utilizing device having data storing section for storing information obtained by encoding data contents and content identification information specifying the data contents, a utilization permitting device for generating utilization permission information used to decode data contents desired by a user and information converting section for loading data contents requested by the user from the data storing section and decoding the data contents only in the case where utilization permission information is generated by the utilization permitting device.

Abstract: A set of a management-use memory medium in which is written various type of regulatory information (limit I of use of software, limit L of production of the next generation, a number K of generations showing up to what generation backup copies can be produced, software identification information PID, etc.) and a software memory medium in which the software is stored is established and use of the software is allowed under the restrictions of this regulatory information. Further, the software memory medium and the management-use memory medium may be provided in the same memory medium or the two may be constituted as separate memory media. In the case of the latter separate management system, the software is allowed to be used only when the software identification information PID written in the two match. It is therefore possible to suppress the unauthorized use of software without detracting from the spatial convenience of software use.

Abstract: There is provided a system for refunding payment for software applied to a software distribution system comprising at least one user terminal and a center. The center notifys the user terminal of the deciphering information on condition that a user of the user terminal pays for the software which is supplied to the user terminal in a enciphered form. Then, the user terminal decipheres the enciphered software by using the deciphering information. The refunding system comprises an installation monitoring unit 38a that records whether the software is installed legally and normally. When the user requests the center to refund the paymenet for the software, a refund request unit 38b of the user terminal notifies the center of the installation history along with the refund request. The center determines whether the installation history contains a data indicating that the installing operation of the software is accomplished normally.

Abstract: A software charging system includes a utilization permitting device for giving permission to use a software storing medium storing ciphered programs or data (software); and an authorization center capable of communicating with the utilization permitting device for setting a utilizable amount, totalling utilization amounts and charging a user. The utilization permitting device includes: a utilization permission processing part having a clock for obtaining date and time data, and having a date and time data storing unit for storing obtained date and time data until obtaining next data and time data; and a utilization amount managing part for calculating a software utilization amount of an end user. A software utilization amount is managed based on the number of days at the utilization permission processing part.

Abstract: In accordance with the present invention, there is provided a transformation pattern generating mechanism comprising: a key input section for inputting a key for encryption; a transformation pattern generating section for generating a transformation pattern for transformation of input data; and an output section for outputting the generated transformation pattern; wherein, when a number sequence corresponding to a predetermined transformation pattern is input as the key to the key input section, said transformation pattern generating section generates and outputs the predetermined transformation pattern corresponding to the number sequence.

Abstract: Moving-picture data in a frame is encoded without depending on another frame of moving-picture data, and moving-picture data in a frame is encoded depending on another frame of moving-picture data. Whether each frame of moving-picture data is a frame which was encoded without depending on another frame of moving-picture data or which was encoded depending on another frame of moving-picture data is determined. The frame of moving-picture data was thus determined as having been encoded without depending on another frame of moving-picture data. The enciphered moving-picture data includes the frame of moving-picture data and the frame of moving-picture data which was determined as being the frame which was encoded depending on another frame of moving-picture data.

Abstract: An enciphered file sharing method is adapted to an area distributed type data processing system in which a plurality of data processing units are coupled via a network and a plurality of users share files while maintaining privacy among the users. The enciphered file sharing method includes the steps of (a) enciphering files using a cipher key and storing enciphered files in directories having a hierarchical tree structure in at least a first data processing unit which functions as a file server, (b) enciphering files having the same access attribute by the same cipher key by assigning one cipher key to each of the directories, and (c) transferring the enciphered files in the network and locally deciphering the enciphered files in at least a second data processing unit which is used by one of the users, where the second data processing unit is different from the first data processing unit.

Abstract: A modular arithmetic unit comprises an input register, a multiple computing section, an adder, and a correcting section. There is provided a multiple table in which multiples of a modulo N are stored to correspond with low-order some bits of an input number T in the input register. The low-order some bits of the input number T are used to look up its corresponding multiple of the modulo N in the multiple table. The adder adds the multiple of the modulo N retrieved from the multiple table and the contents of the input register. This addition is performed n times. The contents of the input register are updated with high-order predetermined bits of the sum in the adder each time addition is performed in the adder. The correcting section makes a correction on the result t of addition by the adder after n additions have been performed.

Abstract: An encryption communication system including: a communication center having at least a key information generating unit for generating key generating information used for encryption communication; and a plurality of user computers, each interconnected by a plurality of paths through the communication center, and each having at least an encryption key generating unit and an encryption processing unit. The communication center generates the key generating information Z based on predetermined modulo arithmetic formula. The user computer sends a password PW to the communication center, receives the key generating information therefrom, and generates an encryption key K used between the user computer and another party's computer based on predetermined modulo arithmetic formula.

Abstract: A cryptographic communications apparatus and method for use with a first terminal, a file server, a key distribution center and a communications channel. The method is made simple by using classical-key-encryption algorithms for electronic generation of session keys. The terminal is verified at a key distribution center, using time stamp and secret identification numbers. Each path is encrypted, with each encrypted message decoded at the key distribution center and file server.

Abstract: Disclosed is a voice band splitting scrambler. To simplify the hardware thereof, the apparatus comprises a band splitting unit (11) for splitting an input voice signal into a plurality of band channels, and a scrambled voice signal generating unit (13) for carrying out spectrum-inverting and band-relocating operations on the respective channels to generate a scrambled voice signal. The scrambled voice signal generating unit (13) includes a modulating unit (15) for band-relocating the respective channels by noninverting carriers of inverting carriers set in different bands respectively; and an adding unit (17) for adding the signals of the noninverting channels and the signals of the inverted channels to each other.

Abstract: Disclosed is a secret speech equipment for ensuring the secrecy of an analog voice signal, and used in voice communication systems such as an analog telephone and mobile radio. The equipment comprises a sub-band signal generating unit for treating input digital samples as frequency-multiplexed signals of voice spectra, to split the frequency-multiplexed signals into a plurality of frequency bands, and thus obtain sub-band signals of the frequency bands, a sub-band signal permutating unit for permuting the sequence of the sub-band signals, and a sub-band signal multiplexing unit for multiplexing the permutated sub-band signals.