Abstract: An information processing system including a data input means (203, 208, 217, 219) for inputting or receiving data, a data compressing means (206) for compressing the data, a decompressing means (221) for decompressing the compressed data and a main storage (209, 222) is provided with an encrypting means (207) for encrypting the data and a decrypting means (220) for decrypting the encrypted data.

Abstract: When a secret is encrypted and stored, it is necessary to provide a countermeasure for the situation where a key is lost (key recovery system). In the present invention, a key recovery system for an enveloped data format in which a common key is used to encrypt a plaintext (secret) and a user's public key is used to encrypt the common key and attached to an encrypted text is provided. In the present invention, only the common key is decrypted to recover the secret without reconstruction of split secret keys kept in a plurality of key storage apparatuses.

Abstract: According to a cryptographic communication system which can safely perform cipher conversion processing when cryptographic communication is performed between terminals using different cipher types, when a terminal 10A-1 connected to a LAN-A using a cryptographic algorithm C1 transmits data to a terminal 10B-1 connected to a LAN-B using a cryptographic algorithm C2, the terminal 10A-1 generates two meaningless data items from the data to be transmitted, decrypts the two generated data items according to the cryptographic algorithm C1, and then transmits the decrypted data to two cryptographic protocol conversion servers and for dividing the data into two data items. Each of the cryptographic protocol conversion servers decrypts each transmitted data item, the re-encrypts the decrypted data according to the cryptographic algorithm C2, and then transmits the data to the terminal 10B-1.

Abstract: In a terminal which received an electronic document with at leastone digital signature, when a user changes the contents of the received electronic document, a new digital signature is produced by enciphering signature data by using a secret key of the user, the signature data including a hash total of the document of a new version, personal information of the user (signatory), and version management information necessary to restore an electronic document of a former version from the electronic document of the new version. The new digital signature and the new version electronic document version are transmitted together with the received digital signature to a next person on a document circulating route.

Abstract: A method and apparatus for carrying out limited encipherment broadcast by generating a cipher key obtained from destination information added to service information are provided. An information service station transmits to each receiving station a random number, destination information for designating a destination station, and enciphered data obtained by enciphering service information by a common key generating by using the random number and destination information. An IC card at each receiving station which is provided in advance with a key generating function from the information service station, generates the common key by using the received random number and destination information only when it is confirmed from the destination information that the receiving station has a data redeption right, and deciphers the enciphered data by using the common key to obtain the original service information.

Abstract: 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.

Abstract: Method and system which permit, among a plurality of terminals, group cipher communication from a desired terminal to a number of desired terminals while ensuring safety of security. A plurality of secret values called master keys which are common to a predetermined subset of IC cards are stored in an IC card. A terminal initially starting communication generates a destination indicator to transmit it to other terminals, selects one of a plurality of master keys stored in an IC card on the basis of the destination indicator, generates a group key by using the selected master key, and performs encipherment and decipherment of a communication message by using the generated group key to carry out broadcast.

Abstract: A plurality of work stations each imparted with a multi-window control function are interconnected through an integrated service digital network (ISDN), wherein control communication route is established among a plurality of stations between which interlocutory communication are to be performed. The work stations transfer control commands by way of the control communication route in accordance with operation by users under the control of an interlocution control program to thereby establish or disconnect a logical communication route between designated application programs of the work stations. So long as the logical communication route is established, the application programs can execute data processing in cooperation with each other. In that case, identical change of display in the windows corresponding to the application programs, respectively, takes place in the work stations.

Abstract: In an information processing system having an upper rank apparatus and an external storage device which performs transmission and reception of data between the storage device and the upper rank apparatus, at least one of encryption and decryption of the data by use of an algorithm controlled by a desired data key is performed in the external storage device, while generation, encryption and decryption of the data key are performed on the upper rank apparatus side. By this configuration, the burden of the upper rank apparatus is largely reduced and the secrecy of data stored in the external storage device can be surely kept without spoiling the throughput of the whole system.

Abstract: Cryptographic techniques for enciphering computer messages or the like include a unit for generating a cipher program for enciphering message data or plaintext by using a plurality of kinds of basic involution processing programs and desired key data, and a unit for enciphering the message data into ciphertext by executing the generated cipher program for the message data. A part of the involution processing program includes a substitution transformation portion and a permutation transformation portion. In accordance with the bit pattern of the above key data, a sequence for executing each of the involution processing programs and a sequence for executing the substitution transformation portion and the permutation transformation portion are determined. The above plurality of transformation processes include an operation of circular shifting to the right or left by X bits and an operation of circular shifting to the right or left by Y bits, with the X and Y being mutually different numbers.

Abstract: A method and apparatus for carrying out limited encipherment broadcast by generating a cipher key obtained from destination information added to service information are provided. An information service station transmits to each receiving station a random number, destination information for designating a destination station, and enciphered data obtained by enciphering service information by a common key generating by using the random number and destination information. An IC card at each receiving station which is provided in advance with a key generating function from the information service station, generates the common key by using the received random number and destination information only when it is confirmed from the destination information that the receiving station has a data reception right, and deciphers the enciphered data by using the common key to obtain the original service information.

Abstract: A cryptographic communication method and system for performing cryptographic communication between a host computer and a given one of plural terminals connected to the host computer by way of a communication network by using a data key designated by the given terminal or the host, wherein the host computer includes a cryptographic processing unit which includes a processing part for performing a public key cryptographic processing by using a pair of a public key and a private key and a common key cryptographic processing by using a common key, and an internal memory for storing master common key and master private key, a storage for recording as user private key information those data that result from the public key cryptographic processing performed by using a master public key on a plurality of user private keys which are in paired relation to user public keys held in the user terminals, respectively, and control means for performing input/output control between the storage and the cryptographic processing

Abstract: An information service system including a plurality of receiving stations and information service facilities. The information service facilities include a memory circuit which stores beforehand a distribution destination information set of receiving station identifiers allocated to the receiving stations, distribution destination information set being disposed in a predetermined order within the memory circuit, a memory circuit for storing a plurality of information to be supplied to receiving stations, an enciphering circuit for generating an enciphering key for optical receiving stations within a group which performs broadcast communications, and enciphering the service information with the enciphering key, and a circuit for transmitting the enciphered service information and service destination codes of service destination receiving stations encoded from the distribution destination information set, through broadcast communications.

Abstract: There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like and a decipher method of deciphering the ciphertext made by the encipher method at a high speed by using the encipher keys. The encipher method and the decipher method are suitable for, particularly, a 32-bit microcomputer and include a process expressed by the function Rot.sub.2 i(x) (i=2, 3, 4) in each process. Rot.sub.2 i(x) is the process to circular shift a data train x of 32 bits to the left or right by 2.sup.i bits (i=2, 3, 4).

Abstract: A mediation can be requested to a computer connected to a communications network when transacting parties A and B effect an electronic transaction and trouble takes place during the transaction. The transaction is effected by a procedure where the transacting party B transmits its preliminary digital signature to the transacting party A. When the transacting party B agrees with the contract document M transacting part A has submitted, the transacting parties A and B exchange their formal signature with each other. These signatures are obtained by coding data including a hash total h(M) obtained by transforming the contract docmument M, identifiers of the transacting parties A and B and a data identifier indicating whether the data are prepared for the preliminary on the formal signature by the public key cryptosystem using a secrete key for one of the transaction parties.

Abstract: There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like and a decipher method of deciphering the ciphertext made by the encipher method at a high speed by using the encipher keys. The encipher method and the decipher method are suitable for, particularly, a 32-bit microcomputer and include a process expressed by the function Rot.sub.2 i(x) (i=2, 3, 4) in each process. Rot.sub.2 i(x) is the process to circular shift a data train x of 32 bits to the left or right by 2.sup.i bits (i=2, 3, 4).

Abstract: A data encrypting system according to the CBC system involves a limitation in a range of a numerical value which expresses data (smaller than a predetermined integer N). The encrypting system has an encrypting apparatus including a block encrypting section for receiving data, which is expressed by an integer value X smaller than a predetermined integer value N, for executing a data conversionC=enc (X)where 0.ltoreq.C.ltoreq.N-1 using an RSA algorithm, and for outputting C; and an arithmetic operating section connected to receive data, as one input, which is expressed by an integer value M smaller than the integer value N, and the output C of the block encrypting section as the other input, for performing an arithmetic operation for both of the inputs so that a resultant arithmetic value is smaller than the integer value N, and for outputting the arithmetic value as an input of the block encrypting section.

Abstract: An electronic transaction in which in order to improve a reliability of message certification by digital signature and enable the use of the digital signature in a formal transaction in place of conventional signature or seal, the following procedures are implemented utilizing the fact that, in a public key cryptograph system represented by an RSA system, a first encoded message derived by encoding a first decoded message by using a public key of a first transacting party is equal to a second encoded message derived by encoding a second decoded message by using a public key of a second transacting party: (a) Check sender/receiver; (b) Add content certification function; (c) Double check the person by the possession of a secret key and the response by a terminal; (d) Add a grace period to the electronic seal; and (e) Send back a tally impression from the receiver to the sender.

Abstract: An IC card having an authentication code which is compared with an authentication code obtained by processing data recorded on the IC card, and permitting the IC card to be used only when agreement is found.