Patent application number | Description | Published |
20120027210 | CRYPTOGRAPHIC SYSTEM, CRYPTOGRAPHIC COMMUNICATION METHOD, ENCRYPTION APPARATUS, KEY GENERATION APPARATUS, DECRYPTION APPARATUS, CONTENT SERVER, PROGRAM, AND STORAGE MEDIUM - A cryptographic communication technology that is based on predicate encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a predicate encryption algorithm and predicate conversion rule information prescribing a conversion rule for converting predicate designation information to predicate information used in the predicate encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first predicate information from input information. The first attribute information or the first predicate information is used for encryption. Encryption information is decrypted with a decryption key generated by using second attribute information or second predicate information obtained from user information by using the other kind of conversion rule information. | 02-02-2012 |
20120033805 | FINITE FIELD CALCULATION APPARATUS, FINITE FILED CALCULATION METHOD, PROGRAM, AND RECORDING MEDIUM - A calculation Π | 02-09-2012 |
20120163588 | FUNCTIONAL ENCRYPTION APPLIED SYSTEM, INFORMATION OUTPUT APPARATUS, INFORMATION PROCESSING APPARATUS, ENCRYPTION PROTOCOL EXECUTION METHOD, INFORMATION OUTPUT METHOD, INFORMATION PROCESSING METHOD, PROGRAM AND RECORDING MEDIUM - An information output apparatus identifies, according to a rule established for each of functional encryption protocols or a rule established for each combination of the protocols, one or more identifiers corresponding to a particular functional encryption protocol or a combination of the particular protocols, sets a particular piece of first correspondence information corresponding to the identifier or identifiers, and outputs first information which is a ciphertext or key information of the functional encryption scheme that corresponds to the particular piece of first correspondence information. An information processing apparatus inputs the first information and second information which is key information or a ciphertext of the functional encryption scheme that corresponds to a particular piece of second correspondence information into a decryption function of the functional encryption scheme and, when the truth value of a logical formula corresponding to the combination of the particular piece of first correspondence information corresponding to the first information and the particular piece of second correspondence information corresponding to the second information is true, generates a decryption result | 06-28-2012 |
20120323981 | PROXY CALCULATION SYSTEM, PROXY CALCULATION METHOD, PROXY CALCULATION REQUESTING APPARATUS, AND PROXY CALCULATION PROGRAM AND RECORDING MEDIUM THEREFOR - A function f(x) is calculated with a calculating apparatus that makes a correct calculation with a low probability. Provided that G and H are cyclic groups, f is a function that maps an element x of the group H into the group G, X | 12-20-2012 |
20130114810 | CRYPTOGRAPHIC SYSTEM, CRYPTOGRAPHIC COMMUNICATION METHOD, ENCRYPTION APPARATUS, KEY GENERATION APPARATUS, DECRYPTION APPARATUS, CONTENT SERVER, PROGRAM, AND STORAGE MEDIUM - A cryptographic communication technology that is based on functional encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a functional encryption algorithm and logical expression conversion rule information prescribing a conversion rule for converting logical expression designation information to logic information used in the functional encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first logic information from input information. The first attribute information or the first logic information is used for encryption. Encryption information is decrypted with a decryption key generated by using second attribute information or second logic information obtained from user information by using the other kind of conversion rule information. | 05-09-2013 |
20130318360 | PROXY COMPUTING SYSTEM, COMPUTING APPARATUS, CAPABILITY PROVIDING APPARATUS, PROXY COMPUTING METHOD, CAPABILITY PROVIDING METHOD, PROGRAM, AND RECORDING MEDIUM - A computing apparatus outputs τ | 11-28-2013 |
20130339413 | PROXY CALCULATION SYSTEM, METHOD, REQUEST DEVICE AND PROGRAM THEREOF - Where G and H are cyclic groups, M is an integer of two or more, i=1, . . . , M, f is a homomorphic function of mapping a member x | 12-19-2013 |
20150358162 | DECRYPTION SERVICE PROVIDING DEVICE, PROCESSING DEVICE, SAFETY EVALUATION DEVICE, PROGRAM, AND RECORDING MEDIUM - A private key is held which conforms to an ElGamal encryption system on a semigroup, calculation of an order of an element of the semigroup being computationally difficult, information corresponding to ciphertext conforming to the ElGamal encryption system is input, a private key s is used to decrypt the information corresponding to the ciphertext in conformance to the ElGamal encryption system, and information corresponding to a result of decrypting the ciphertext is obtained and output. Alternatively, whether it is computationally difficult or easy to calculate the order of the element of the semigroup is determined, and the safety of a decryption service providing device is evaluated based on the determination result. | 12-10-2015 |