### Abstract

[Problem] To provide an encryption calculation which is secure against side channel attacks and which can keep down processing loads. [Solution] This encryption device is provided with a data encryption unit that performs encryption with a white box model in which at least some of multiple rounding functions for sequentially performing encryption processing on input values are tabulated and in which the input and output values of the rounding functions can be recognized from the outside. Each of the aforementioned rounding functions has a tabulated encryption function which encrypts input values in a black box model in which the input and output values can be recognized from the outside and intermediate values cannot be recognized from the outside, and the encryption functions are updated by means of random numbers.

Original language | English |
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IPC | G09C 1/ 00 A I |

Patent number | WO2019031025 |

Filing date | 28/05/2018 |

Country | International Bureau of the World Intellectual Property Organization (WIPO) |

Priority date | 10/08/2017 |

Priority number | JP20170156144 |

Publication status | Published - 14 Feb 2019 |

### Cite this

*WO2019031025*).

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*Encryption device, encryption method, decryption device, and decryption method*, Patent No. WO2019031025, IPC No. G09C 1/ 00 A I.

**Encryption device, encryption method, decryption device, and decryption method.** / 五十部 孝典Takanori (Inventor); 樋渡 玄良Harunaga (Inventor); ボグダノフ アンドレイ, Andrey (Inventor).

Research output: Patent

TY - PAT

T1 - Encryption device, encryption method, decryption device, and decryption method

AU - 五十部 孝典, Takanori

AU - 樋渡 玄良, Harunaga

AU - ボグダノフ アンドレイ, Andrey

PY - 2019/2/14

Y1 - 2019/2/14

N2 - [Problem] To provide an encryption calculation which is secure against side channel attacks and which can keep down processing loads. [Solution] This encryption device is provided with a data encryption unit that performs encryption with a white box model in which at least some of multiple rounding functions for sequentially performing encryption processing on input values are tabulated and in which the input and output values of the rounding functions can be recognized from the outside. Each of the aforementioned rounding functions has a tabulated encryption function which encrypts input values in a black box model in which the input and output values can be recognized from the outside and intermediate values cannot be recognized from the outside, and the encryption functions are updated by means of random numbers.

AB - [Problem] To provide an encryption calculation which is secure against side channel attacks and which can keep down processing loads. [Solution] This encryption device is provided with a data encryption unit that performs encryption with a white box model in which at least some of multiple rounding functions for sequentially performing encryption processing on input values are tabulated and in which the input and output values of the rounding functions can be recognized from the outside. Each of the aforementioned rounding functions has a tabulated encryption function which encrypts input values in a black box model in which the input and output values can be recognized from the outside and intermediate values cannot be recognized from the outside, and the encryption functions are updated by means of random numbers.

M3 - Patent

M1 - WO2019031025

Y2 - 2018/05/28

ER -