Abstract: In a buffer and a state included in a pseudorandom number generating apparatus, the state has the configuration of assuming that the unit length of data processing is n, the state has a size of 3×n bits, and the buffer has a capacity of 32×n bits, and according to clock control, a state transformation section (state transformation function) for conducting a state alteration from time t to time t+1 uses a nonlinear function F (having an n-bit input and an n-bit output) twice, or two different nonlinear functions F and G respectively once. The state transformation section has such a configuration that a nonlinear function such as a round function of a block cipher sufficiently evaluated as to the cryptographic security and implementation.

Abstract: In a signature generating method where not necessarily all of a plurality of signature generating devices work together each time to generate signatures, the present invention seeks to correctly and securely reflect data relating to previous signatures.

Abstract: In a buffer and a state included in a pseudorandom number generating apparatus, the state has the configuration of assuming that the unit length of data processing is n, the state has a size of 3×n bits, and the buffer has a capacity of 32×n bits, and according to clock control, a state transformation section (state transformation function) for conducting a state alteration from time t to time t+1 uses a nonlinear function F (having an n-bit input and an n-bit output) twice, or two different nonlinear functions F and G respectively once. The state transformation section has such a configuration that a nonlinear function such as a round function of a block cipher sufficiently evaluated as to the cryptographic security and implementation.

Abstract: This invention provides a method for identifying a purchaser who purchased content from which an illegal copy was produced. A provider system encrypts a content purchased by the purchaser using a public key of a purchaser system and sends the encrypted content to the purchaser system. The purchaser system creates a digital signature of the content with the use of a private key of its own and embeds the created digital signature into the received content. When an illegal copy is found, the provider system verifies the digital signature, embedded in the illegal copy as a digital watermark, to identify the purchaser who purchased the content from which the illegal copy was produced.

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: The technology includes the steps of: associating material-object identification code identifying each individual material object with material-object information representing information about material object identified by identification code and storing identification code and material-object information in material-object information database in each of business categories; sending code and information stored in database in each business category; integrating items of information having same code with each other among codes and items of information received from database in each business category to generate integrated material-object information, associating identification code with integrated material-object information identified by code and storing identification code and integrated material-object information in integrated database; requesting to send integrated material-object information associated with given identification code; reading requested integrated material-object information from integrat

Abstract: Hash values, keys and cipher text which have a high degree of data scrambling are generated rapidly. When a message is sent, divisional data of the message are input, and injection extension processing is performed so that the data length of output data is longer than the data length of input data. Further, hash values are generated by a hash function containing multiplication processing, cyclic shift processing, etc.

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: 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: A digital signature generating/verifying method using a public key encryption scheme which ensures high security, reduction in length of the digital signature and independency of the length of the digital signature on that the order of a base point. In generating a digital signature, a first hash value (e) satisfying a condition that e=H(M) is determined for a given message (M) by using a hash function (H), a numerical value (x) is obtained from translation of a random number, a hash value (r) satisfying a condition that r=h(x) is determined by using a hash function (h) whose output value is shorter than that of the first hash function (H), and the digital signature is generated by using the hash values (e) and (r) as determined.

Abstract: An identification code management method and management system includes that the issue and distribution of an ID code having a message authentication code are managed thereby to efficiently and reliably manage a material object using the ID code. An electronic circuit chip with an ID code having a message authentication code stored in a read-only area is used as an identification tag. The information at an ID code order receiving terminal and an identification tag production factory terminal are consolidated and collectively managed at an ID code management terminal. Thereby, the ID code management terminal is inquired of highly confidential information or requested to process the information as required so that an ID code utilization terminal is not required to store the same information.

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: The present invention provides a symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection.

Abstract: The present invention provides a symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection.

Abstract: Encrypting/decrypting conversion method and apparatus capable of controlling dynamically cyclic shift independent of data to undergo encrypting/decrypting conversion includes two or more different fixed circulating shift processing means for shifting cyclically the data by a fixed bit number leftward or rightward, a cyclic shift processing selecting means for selecting fixed cyclic shift processing means. The selecting sequence determined by the cyclic shift processing means is determined on the basis of data for determining the shift number selecting sequence.

Abstract: A key recovery method and system capable of key recovery without informing a third party of one's own secret key are disclosed. For realization of the method, a transmitting information processor generates a data value satisfying a relational expression by which if one of data obtained by converting a first public key and used as a cipher text generating parameter and data obtained by converting at least one second public key is decided, the other can be determined. The transmitting processor transmits a cipher text applied with the generated data value to a first receiving information processor which has a secret key paired with the first public key and at least one second receiving information processor which has a secret key paired with the second public key.

Abstract: In the process of compressing and encrypting data, without increase of a processing time, a cipher capability is secured against the latest cryptanalysis such as differential and linear cryptanalyses. The differential and linear cryptanalyses are executed to collect plural pair of plaintext and cryptosystem for the same key and perform the statistical operation for estimating the key. An I/O process is executed to receive plaintext data and generate a random number. Then, an operation is executed to generate a different key for each data on the random number and set the key to a work key. The encrypted intermediate result or the pre-encrypted result is fed back for frequently changing the work key. These series of operations makes it possible to protect the ciphertext from the differential and the linear cryptanalyses.

Abstract: A method and apparatus for generating a highly secured hash value without deteriorating the processing speed is provided. A hash function such that when a message M is given, the message M is compressed so as to have a certain kind of characteristics of cipher is realized. In a step, (1) one to one expanding process so that divided data of the message is inputted and longer data is outputted is executed, and (2) a plurality of cyclic shifting processes in which the number of shifting is different are executed. Consequently, the hash function can be calculated at higher speed than a conventional method of simple repetitive compression of divided data of a message.

Abstract: This invention provides a method for identifying a purchaser who purchased content from which an illegal copy was produced. A provider system encrypts a content purchased by the purchaser using a public key of a purchaser system and sends the encrypted content to the purchaser system. The purchaser system creates a digital signature of the content with the use of a private key of its own and embeds the created digital signature into the received content. When an illegal copy is found, the provider system verifies the digital signature, embedded in the illegal copy as a digital watermark, to identify the purchaser who purchased the content from which the illegal copy was produced.

Abstract: Hash values, keys and cipher text which have a high degree of data scrambling are generated rapidly. When a message is sent, divisional data of the message are input, and injection extension processing is performed so that the data length of output data is longer than the data length of input data. Further, hash values are generated by a hash function containing multiplication processing, cyclic shift processing, etc.