Apparatus and method for data encryption with block selection keys and data encryption keys

摘要

Disclosed is a data encryption apparatus strong to differential cryptanalysis, which is now the most influential cryptanalysis method. According to the data encryption apparatus, input data is divided into N blocks, 1 to N-1 blocks of which is selected by a first selection unit with a block selection key. Then the selected blocks of data is compressed into a single block of data in a first combination unit, and encrypted with a data encryption key in an F-function unit. A second combination unit combines the blocks of data not selected in the first selection unit with the output of the F-function unit by XOR. An output unit outputs N blocks of data arranged in the same order as the initial N blocks, in which the 1 to N-1 blocks selected in the first selection unit are outputted without any change, and the other blocks being the outputs of the second combination unit.