Sony Corporation

Technical University of Denmark

Sony Group Corporation

Andrey Bogdanov

Takanori Isobe

Harunaga Hiwatari

There is provided an encryption device to ensure strong security without using a random number in a white-box model. The encryption device includes: an encryption part configured to encrypt an input value using a black-box model in which input/output values are able to be recognized from the outside and an intermediate value is not able to be recognized from the outside; and a key generation part configured to encrypt the input value to the encryption part to generate a cryptographic key of the encryption part using a white-box model in which the input/output value and the intermediate value are able to be recognized from the outside.

Encryption device, encryption method, decryption device, and decryption method

There is provided an encryption device that is secure against a side channel attack, and can suppress a processing load. The encryption device includes a data encryption part in which at least part of a plurality of round functions for successively performing encryption processing on an input value is tabulated to be encrypted using a white-box model in which input/output values of the round function is able to be recognized from the outside. Each of the round functions includes a tabulated encryption function for encrypting an input value using a black-box model in which the input/output values are able to be recognized from the outside and an intermediate value is not able to be recognized from the outside, and the encryption function is updated with a random number.

There is provided an encryption device including a data encryption unit configured to conduct encryption on the basis of a white box model in which at least a part of a plurality of round functions for sequentially conducting encryption processing on an input value is tabulated, and input and output values of the round function are recognizable from an outside. The plurality of round functions each have an encryption function that is tabulated and encrypts an input value in a black box model in which input and output values are recognizable from the outside and an intermediate value is not recognizable from the outside.

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Kongens Lyngby, Denmark

Andrey Bogdanov