Abstract: According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.

Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length; generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.

Abstract: An encryption processing part of a controller of each of user devices specifies components of content as encryption target parts, creates an encryption key creation key by reading out a public key, for each of the encryption target parts, of a second user who is allowed to view the encryption target part, raising a secret key of an administrator of the content data to the power of the public key thus read out, and calculating a remainder, encrypts random numbers each corresponding to each of the encryption target parts by using the encryption key creation key, creates an encryption key for each of the encryption target parts, and encrypts, by using the encryption key created for each of the encryption target parts, each of the encryption target parts corresponding to the encryption key.

Abstract: An electronic data disclosure system including a submitter device, an electronic disclosure device, and a reader device is provided. The submitter device is configured to execute the steps of, creating submission data and transmitting the submission data to the electronic disclosure device. The electronic disclosure device is configured to execute the steps of receiving the submission data from the submitter device, giving a digital signature to the submission data received and disclosing the submission data to which the digital signature has been given. The reader device is configured to execute the steps of obtaining the submission data disclosed by the electronic disclosure device, to which the digital signature has been given, displaying the submission data to which the digital signature has been given, performing signature verification of the submission data to which the digital signature is given and displaying a result of the signature verification.

Abstract: According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.

Abstract: Disclosure of information is controlled selectively depending on users such that a plurality of users having different roles bearing no inclusive relation with one another can access the same area. Content is divided into a plurality of areas. For each of the areas obtained by division, secret keys (encryption/decryption keys in symmetric-key cryptography) are generated. The generated keys are encrypted using public keys in public-key cryptography, which are set in advance for the users depending on their respective roles. In the case where the content is to be disclosed to a plurality of users having different roles, the encryption of secret keys is performed separately for each user. These encrypted contents and encrypted secret keys are used to generate encrypted text.

Abstract: A need exists for a technology for guaranteeing the authenticity of an electronic document, and an information disclosure system, which can guarantee the authenticity of a disclosed document and delete information regarded as inappropriate for disclosure. An electronic document is divided into components, and a random number generated from a seed value is concatenated to each of the components. A hash value is calculated for each of the components with which the random numbers have been concatenated. The calculated hash values are further concatenated using a hash function to generate data to which an digital signature is applied.

Abstract: Techniques of improving the safety of an information processing system at low cost are provided, the information processing system having an OS provided with an access control function based upon discretionary access control for preventing illegal accesses to files. A method and apparatus for providing the information processing system with functions and areas usable only by a specific user different from a system administrator. The areas are provided with an access control function in order to prevent the access control function from being tampered.

Abstract: A reliably safe storage system is provided which makes provable the status of a file stored in a storage server at a time specified by a user and creates evidence information that will be effective in future. In response to a file status fixing request from the user over a network, a storage server generates file fixing guarantee data, including data publicized by a publication server, and saves the generated data with the file associated with the generated data.

Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length, generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using in the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.

Abstract: A time stamp generating system has a time distribution server for generating time data depending on time and a user PC for holding time certification objective digital data. The time distribution server generates time data corresponding to a time point and distributes the time data. The user PC calculates time stamp generating data by using the time certification objective data as an input, acquires the time data generated by the time distribution server, and processes the time data on the basis of the time stamp generating data to obtain a time stamp.

Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length; generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.

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 symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length, generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext blocks and the random number block, the feedback value being fed back for using in the operation on another plaintext blocks, and performing an encryption operation using the one plaintext blocks, random number block, and feedback value.

Abstract: A defect detector having: a first optical system including a first light source to irradiate a surface of a subject with coaxial incident-light while scanning, and a first imaging device to receive light regularly reflected from the subject and change the light to a first electrical signal to form a first electrical image; a second optical system including a second light source to irradiate the surface of the subject with inclined light while scanning, and a second imaging device to receive light scattered at the subject and change the light to a second electrical signal to form a second electrical image, in which the inclined light of the second light source does not meet the coaxial incident-light of the first light source; and a computer to compare the first electrical signal with a predetermined first threshold to detect a concavo-convex defect on the surface of the subject, and to compare the second electrical signal with a predetermined second threshold to detect a blocky color defect on the surface of

Abstract: An original signature can be verified even if a signed image data is properly altered in its portion. The digital image data is divided into a plurality of configurational elements, and each of the feature values of the elements are calculated, so that the signature is created by combining the feature values. In case the configurational elements are to be deleted, they are substituted by substitutive data, and only the feature values are stored. The verification is created by using the stored feature values as the substituted elements and by using the calculated feature values as the remaining elements, so that the signature is verified with the signature attached to the digital image data.

Abstract: A network system capable of preventing the leakage of a confidential file by an inadvertent act of a transmitting party and capable of meeting the requirement for an arbitrary file format is disclosed. A label indicating a security level (“confidential” or “unclassified”) is attached to the file in a client terminal, which transmits the labeled file outside. A transmission management program on a gateway server checks the label of the file, and in the case where the security level is “unclassified”, transmits the file to an external network. Also, a label management program manages the labeled file in the client terminal.

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: To provide a verification record preservation function for keeping for a long time an evidential property of a verified signature to a user side apparatus and to provide services for insuring reliability of a signature of a user. A verification record preservation program creates a verification log recording a verification object signature, a signature log and a deposited publication signature log entry that are used for verification. A publishing organization side apparatus provides services that can reliably execute chain verification with reliability while taking convenience of users into consideration, such as a publication reminder service for preventing forgetfulness of publication, a publication notice for notifying publication of other user, verification vicarious execution for a user, and so forth.

Abstract: To provide a secure cryptographic device such as an IC card which can endure TA (Timing Attack), DPA (Differential Power Analysis), SPA (Simple Power Analysis), or the like as an attaching method of presuming secret information held therein, when the secret information held in the card or another information which is used in the secret information or an arithmetic operation using such secret information when such an arithmetic operation is performed is shown by a plurality of expressing methods and the arithmetic operation is performed, thereby making an arithmetic operation processing method different each time the arithmetic operation is performed and making each of an arithmetic operation time, an intensity of a generated electromagnetic wave, and a current consumption different.