Kabushiki Kaisha Toshiba

Tsukasa Endo

Yuichi Komano

Hideo Shimizu

Atsushi Shimbo

Hanae Ikeda

Koichi Fujisaki

Kazuo Ohta

Mitsugu Iwamoto

According to an embodiment, a generating device includes a first key generator, a second key generator, and an output unit. The first key generator is configured to generate a first key according to a first key rule in which the first key is generated from a random number, the first key being a bit sequence. The second key generator is configured to generate a plurality of second keys according to a second key rule in which the second keys are generated from the first key, the second keys being bit sequences partly correlated to one another. The output unit is configured to output the first key and at least one of the second keys.

Generating device, encryption device, decryption device, generating method, encryption method, decryption method, and computer program product

According to an embodiment, an encryption device performs encryption processing using an encryption key and calculates encrypted data from plain data. The encryption device includes: a register; an input unit configured to receive plain data; a first partial encryption unit configured to calculate first intermediate data from the plain data; a second partial encryption unit configured to calculate (i+1)-th intermediate data based on i-th intermediate data and the encryption key; a first transform unit configured to: transform j-th intermediate data into j-th transformed data; and store the j-th transformed data in the register; and a second transform unit configured to transform the j-th transformed data into the j-th intermediate data; a third partial encryption unit configured to calculate encrypted data from the N-th intermediate data. The second partial encryption unit is configured to repeat processing to calculate (j+1)-th intermediate data while j is equal to from 1 to N&#x2212;1.

Encryption device

According to one embodiment, in an encryption device, a segmentation unit segments masked plain data into pieces of first segmented data. A first processing unit generates pieces of second segmented data from the pieces of first segmented data. A nonlinear transform unit generates pieces of third segmented data transformed from the pieces of second segmented data. A data integration unit integrates fourth segmented data to generate masked encrypted data. An unmask processing unit generates encrypted data from the masked encrypted data. The exclusive OR of the pieces of second segmented data matches the exclusive OR of input data, subjected to nonlinear transform processing and calculated from the plain data, and the first mask. The exclusive OR of the pieces of third segmented data matches the exclusive OR of transform data, obtained when the nonlinear transform processing is performed on the input data, and the second mask.

Growing community of inventors

Tokyo, Japan

Tsukasa Endo