摘要:
A computer system having resistance to timing attacks based on measuring processing times by encrypting or decrypting a plain text or ciphertext by converting the partial data related to the plain text or the encrypted text into conversion data. In the system, a conversion table includes one piece of conversion data corresponding to the partial data at a start position of a line table area and includes data not associated with the conversion in the other position. In the system, a computer program includes an operation instruction for calculating a predetermined position of the conversion data in the conversion table by using acquired partial data and a read instruction for reading out the conversion data from the calculated position.
摘要:
The present invention provides a password recovery system that re-supplies a password to only the legitimate user of the password. The password recovery system includes a memory card with CPU and a mobile phone. When a password needs to be recovered, a phone call is made, to the mobile phone, from a telephone connected to a phone line whose phone number is registered in advance into the memory card with CPU. The mobile phone then obtains the telephone number of the phone line via a caller's telephone number notifying service. It is judged whether the obtained telephone number and the registered phone number are the same, and when they are the same, the password stored in the memory card with CPU will be re-supplied so that the user can recover it.
摘要:
In a content-log analyzing system, content includes additional information indicating, according to a property of the content, whether or not to record communication of the content in a content-log. When transmitting content to a TV or a PC, a data-communication controlling device judges whether or not to record the communication in a content-log based upon additional information of the content, and when judging affirmatively, generates and stores content-log information. A content-log analyzing server obtains the content-log stored in the data-communication controlling device, and analyzes the obtained content-log.
摘要:
A content distribution system distributes contents. The content distribution system includes a key issuing center, a server, eight output apparatuses, and a communication path that connects them to each other. The key issuing center and each of the output apparatuses are previously given an individual key shared between them. For example, the key issuing center shares individual key IKa with an output apparatus, individual key IKb with an output apparatus, and individual key IKh with an output apparatus.
摘要:
This relates to an imaging device in which the necessary monitoring of an individual can be realized, while still maintaining protection of an individual's privacy. The imaging device includes an encryption key storage unit in which encryption key data is stored for an individual, an object judging unit operable to judge whether or not the captured video is of the individual, and a limited-capture video generation unit operable to (i) convert a part of the captured video that includes the individual into encrypted video, (ii) generate limited-capture video, which includes the encrypted video, when said object judging unit judges that the captured video includes the individual, and (iii) output the captured video, which does not include the encrypted video, when said object judging unit judges that the captured video does not include the individual.
摘要:
Provided is a program conversion apparatus for generating a secret holding program, which disables a malicious analyzer from analyzing the an original program easily.The program conversion apparatus generates a first instruction group for acquiring values to assign to selection parameters; a second instruction group that includes an instruction group for acquiring, based on an arithmetic expression that uses the selection parameters, a selection identifier showing a selection-target data piece to be processed next; a third instruction group for updates a value of each selection parameter so as to reflect one of (a) a selection identifier showing one of the selection-target data pieces that has already been processed, and (b) at least one of one or more values that have already been assigned to the selection parameters; and selection-target data pieces that, by processing in a predetermined order, output an execution result identical to a result of the original program, each of the selection-target data pieces being in correspondence with a different selection identifier. The program conversion apparatus generates the secret holding program so as to include the first instruction group, the second instruction group, the third instruction group and the selection-target data pieces.
摘要:
An encryption device, a decrypting device, a secret key generation device, a copyright protection system and a cipher communication device including: a CRL memory unit memorizing a CRL, a device key ring memory unit memorizing a specific device key KD_A in every IC card used in a decrypting device, a content key memory unit memorizing a content key Kc, which is a secret key for decrypting content, and a hashing function processing unit calculating a hashing value of the CRL memorized in the CRL memory unit. The devices further including an Ex-OR unit carrying out an exclusive OR between the hashing value and the device key KD_A memorized in the device key ring memory unit, and an Enc unit encrypting the content key Kc memorized in the content key memory unit using an output value of an Ex-OR unit.
摘要:
A signature generation apparatus is capable of making a value used in signature generation processing difficult to analyze. In the signature generation apparatus, a random number generation module generates a len-bit random number u, a selection module converts the generated random number u into a bit expression, and acquires element pairs corresponding to the bit values from a table memory unit. A random element generation module applies a basic operation of a first group G and a second group to all acquired element pairs, and calculates an element Pk on the first group G and an element Pak on the second group Ga. The signature generation apparatus generates a digital signature S for a message m with use of a transformation module, a main operation module, an inverse transformation module, a multiplication module, a division module, and a signature data generation module.
摘要:
A signature generation apparatus capable of preventing transcript attack on signature data is provided. The signature generation apparatus performing a digital signature operation with the use of a signature key: stores the signature key; performs the digital signature operation on signature target data with the use of the signature key to generate signature data; counts the cumulative count of digital signature operations having been performed by the signature generation unit with the use of the signature key; judges whether the cumulative count has reached a predetermined count; and inhibits the use of the signature key in the digital signature operation from then onward in a case where the judgment unit determines that the cumulative count has reached the predetermined count.
摘要:
A recording apparatus for copying a digital stream recorded on a first recording medium using a code format compatible with the first recording medium to a second recording medium after the digital stream has been converted to a code format compatible with the second recording medium, comprising: a detection unit operable to detect a plurality of devices that are available for distributed processing from devices connected to the recording apparatus via a network; an allocation unit operable to divide the digital stream at one or more predetermined points on a playback time axis and to allocate the divided portions to the detected devices respectively; a transmission unit operable to transmit the allocated portions to the respective detected devices; a control unit operable to control the detected devices to perform transcoding for converting a code format of the allocated portions to the code format compatible with the second recording device; and a writing unit operable to receive converted portions resulting from the transcoding from the detected devices and to write the received portions to the second recording medium.