# Taichi Isogai, Tokyo JP

## Taichi Isogai, Tokyo JP

Patent application number | Description | Published |
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20080247597 | DEVICE FOR DETECTING DIGITAL WATERMARK - A device includes: a reception unit that receives video image; an extraction unit that extracts the watermark patterns from the video image; a storage unit that stores an accumulated information pieces and a number of accumulation times; a calculation unit that calculates degrees of correlation between the accumulated information pieces and the watermark patterns; an accumulation unit that accumulates the watermark patterns in one of the accumulated information pieces having the degree of correlation that is larger than a threshold value and is the largest among the calculated degrees of correlation; a selection unit that selects a top N-pieces of the accumulated information pieces stored in the storage unit having largest number of the accumulation times, where N is a positive integer; and a watermark value calculation unit that obtains a digital watermark value from the accumulated information pieces selected by the selection unit. | 10-09-2008 |

20100046741 | APPARATUS, METHOD, AND COMPUTER PROGRAM PRODUCT FOR DECRYPTING, AND APPARATUS, METHOD, AND COMPUTER PROGRAM PRODUCT FOR ENCRYPTING - An input unit inputs encrypted data that elements of a subgroup and expressed in an affine representation. A transforming unit transforms the inputted encrypted data into projective representation data expressed in a projective representation. A plain data calculating unit subjects the projective representation data to a decrypting process previously defined by a cryptosystem, thereby calculating plain data expressed in the projective representation. | 02-25-2010 |

20100046742 | APPARATUS AND COMPUTER PROGRAM PRODUCT FOR PERFORMING DATA COMPRESSION PROCESSING USING ALGEBRAIC TORUS - An encryption processing unit executes an arithmetic operation decided in advance and outputs an arithmetic result as an element on an algebraic torus. A compressing unit outputs, when the arithmetic result is an exceptional point representing an element on the algebraic torus that cannot be compressed by a compression map for compressing an element on the algebraic torus into affine representation, a compression result obtained by compressing the arithmetic result according to the compression map and outputs, when the arithmetic result is the exceptional point, an element belonging to a specific set decided in advance that does not overlap a set to which a compression result obtained by compressing the arithmetic result, which is not the exceptional point, belongs. | 02-25-2010 |

20100046743 | APPARATUS FOR PERFORMING DATA COMPRESSION PROCESSING USING ALGEBRAIC TORUS - A compressing unit compresses an element on an algebraic torus into affine representation according to a compression map. A determining unit determines whether a target element on the algebraic torus to be compressed is an exceptional point representing an element on the algebraic torus that cannot be compressed by the compression map. The compressing unit generates, when it is determined that the target element is the exceptional point, a processing result including exceptional information indicating that the target element is the exceptional point, and generates, when it is determined that the target element is not the exceptional point, a processing result including affine representation obtained by compressing the target element according to the compression map. | 02-25-2010 |

20100046745 | ENCRYPTING APPARATUS, DECRYPTING APPARATUS, CRYPTOCOMMUNICATION SYSTEM, AND METHODS AND COMPUTER PROGRAM PRODUCTS THEREFOR - A decrypting apparatus that decrypts encrypted data that has been encrypted first data containing plain data, the encrypted data being represented by using an affine representation F_{p̂m}×F_{p̂m}̂*(where p: a prime number; m: a natural number; and ̂: exponentiation) obtains encrypted data represented in a vector format and a secret key corresponding to a public key and judges whether a vector component contained in the encrypted data is the affine representation F_{p̂m}×F_{p̂m}̂*. Further, based on the result of the judging process, the decrypting apparatus maps the vector component onto each of the members of an algebraic torus by forming a decompression map and decrypts the encrypted data mapped onto each of the members of the algebraic torus, by using the secret key, therefore obtains the plain data. | 02-25-2010 |

20100046746 | PARAMETER GENERATING DEVICE AND CRYPTOGRAPHIC PROCESSING SYSTEM - A parameter generating device includes an input receiving unit that receives a degree n of an algebraic torus T including a group G in which a cryptosystem used in a torus-compressed public key cryptosystem is defined, a size W of a finite field F, and a size S of the group G, an extension-degree determining unit that determines an extension degree m of a finite field Fp | 02-25-2010 |

20100049777 | REPRESENTATION CONVERTING APPARATUS, ARITHMETIC APPARATUS, REPRESENTATION CONVERTING METHOD, AND COMPUTER PROGRAM PRODUCT - When converting an affine representation representing a 2r-th degree algebraic torus T | 02-25-2010 |

20100063986 | COMPUTING DEVICE, METHOD, AND COMPUTER PROGRAM PRODUCT - In a computing device that calculates a square of an element in a finite field, a vector representation of the element in the finite field is accepted. The vector representation includes a plurality of elements. The computing device performs a multiplication operation on a base field using the accepted elements, and obtains a multiplication value. The multiplication operation is determined by a condition under which the element in the finite field is placed in an algebraic torus. The computing device performs an addition and subtraction operation using the obtained multiplication value and the accepted elements, and obtains a calculation result of the square of the element. The addition and subtraction operation is determined by the condition. The computing device then outputs the calculation result. | 03-11-2010 |

20120124114 | ARITHMETIC DEVICE - According to one embodiment, a representation converting unit converts a set of n elements (h | 05-17-2012 |

20120150931 | DECOMPRESSING APPARATUS AND COMPRESSING APPARATUS - According to one embodiment, a decompressing apparatus includes an input unit, a calculating unit, a first selecting unit, and a decompressing unit. The input unit inputs additional data, which is obtained based on trace expression data in which an element in a subgroup of a multiplicative group of a finite field is trace-expressed and affine expression data in which the trace expression data is affine-expressed, and the trace expression data. The calculating unit calculates a plurality of solutions of simultaneous equations derived by the trace expression data. The first selecting unit selects any of a plurality of items of affine expression data in which the element is affine-expressed based on the additional data, the affine expression data being found from the solutions. The decompressing unit decompresses the selected affine expression data to the element. | 06-14-2012 |

20120239721 | ARITHMETIC DEVICE, METHOD, AND PROGRAM PRODUCT - An arithmetic device includes an input unit inputting data that are elements of a group; a converting unit is configured, when the input data are in a second representation, to convert the input data into a first representation and to perform arithmetic operation on the converted first representation using an operand in the first representation in which at least one subcomponent is a zero element to convert the converted first representation into first converted data expressed in the first representation, and when the input data are in the first representation, to perform arithmetic operation on the input data using the operand in the first representation in which at least one subcomponent is a zero element to convert the input data into second converted data expressed in the first representation; and an operating unit that performs arithmetic processing on the first or the second converted data using secret information. | 09-20-2012 |

20130166080 | INFORMATION PROCESSING DEVICE AND POWER USE ADJUSTMENT SYSTEM - An example information processing device includes first and second receiving units, a deciding unit, and first and second transmitting units. The first receiving unit receives adjustment limit information from a plurality of first external devices. The deciding unit determines adjustment rules on the basis of the adjustment limit information. The first transmitting unit transmits the adjustment rules to second and third external devices. The second receiving unit receives determination information from a fourth external device. The second transmitting unit transmits the adjustment rules to the first external devices when integrated schedule information satisfies a condition. When the integrated schedule information does not satisfy the condition, the deciding unit changes the adjustment rules. When the deciding unit has changed the adjustment rules, the first transmitting unit transmits new adjustment rules to the second and third external devices. | 06-27-2013 |

20130218939 | EXPONENTIATION CALCULATION APPARATUS AND METHOD FOR CALCULATING SQUARE ROOT IN FINITE EXTENSION FIELD - In a computing device that calculates a square of an element in a finite field, a vector representation of the element in the finite field is accepted. The vector representation includes a plurality of elements. The computing device performs a multiplication operation on a base field using the accepted elements, and obtains a multiplication value. The multiplication operation is determined by a condition under which the element in the finite field is placed in an algebraic torus. The computing device performs an addition and subtraction operation using the obtained multiplication value and the accepted elements, and obtains a calculation result of the square of the element. The addition and subtraction operation is determined by the condition. The computing device then outputs the calculation result. | 08-22-2013 |

20130243191 | ENCRYPTION KEY GENERATING APPARATUS - According to an embodiment, an encryption key generating apparatus includes first to third calculators. The first calculator executes a first round operation to a first portion of first data. The second calculator executes the first round to a second portion of second data pieces. Each second data piece includes the first portion of the first data to which the first round operation has been completed and the second portion obtained by changing at least a part of the first data other than the first portion. At least a part of the second portion is different from that of each of the other second portions. The second calculator executes the first round operation to each second portion. The third calculator unit executes operations of the second and subsequent rounds to the second data pieces. | 09-19-2013 |