Title: Cryptographic apparatus, cryptographic method, and storage medium thereof
Application Number: 200510056533 Application Date: 2005.01.07
Publication Number: 1648967 Publication Date: 2005.08.03
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G09C1/00
Applicant(s) Name: Samsung Electronics Co., Ltd. Address:
Inventor(s) Name:
Attorney & Agent: wang zhisen huang xiaolin
Abstract:
     A cryptographic apparatus, a cryptographic method, and a computer readable storage medium provide for conversion between Boolean-masked data and arithmetic-masked data in a manner that allows for a reduction in computational overhead and hardware overhead. The cryptographic apparatus comprises: a first masking circuit which receives a first random number and data and outputs first-masked data; and a second masking circuit which receives a second random number and the first-masked data output from the first masking circuit, and outputs second-masked data. The second masking circuit comprises: an AND circuit which performs an AND operation between the first-masked data and the second random number; a shift circuit which receives the output signal of the AND circuit, and shifts the received output signal in a predetermined direction by predetermined bits; and a subtractor which receives the first-masked data and the output signal of the shift circuit, performs arithmetic subtraction of the output of the shift circuit form the first-masked data, and outputs second-masked data. The first-masked data is Boolean-masked data and the second-masked data is arithmetic-masked data.
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