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

A data encryption apparatus for encrypting input data after dividing the input data into N blocks of data each consisting of M bits wherein N is an integer greater than 2 and M is an integer of 2 or more, the data encryption apparatus comprising:

• a first selection unit for selecting L blocks among the N blocks, L being an integer of 1 to N-2;
• a block selection information generation unit for generating block selection information, based on a block selection key and the blocks of data outputted from the first selection unit;
• a second selection unit for selecting 1 to N-L-1 blocks among N-L blocks that are not selected in the first selection unit using the information outputted from the block selection information generation unit;
• a third selection unit for selecting all of the other blocks that are not selected in the first and second selection units;
• a first combination unit for combining the blocks of data selected in the first and second selection units into a single block of data and outputting the M-bit data;
• an F-function unit for encrypting the M-bit data outputted from the first combination unit using a data encryption key and outputting resultant M-bit data;
• a second combination unit for combining the M-bit data outputted from the F-function unit with each of the blocks of data selected in the third selection unit by XOR;
• and
• an output unit for outputting all the blocks of data outputted from the first and second selection units and the second combination unit after permuting all the blocks.

A data encryption apparatus for encrypting input data after dividing the input data into N blocks of data each consisting of M bits, wherein N is an integer greater than 2 and M is an integer greater than 1, the data encryption apparatus comprising:

• a grouping unit for grouping the N blocks into L superblocks, L being an integer greater than 1;
• a first selection unit for selecting one block from each of the L superblocks using a block selection key;
• a second selection unit for selecting all the other blocks in each of the superblocks;
• an F-function unit for encrypting L blocks of data selected in the first selection unit using a data encryption key and outputting the encrypted L blocks of data, the encrypted blocks of data being divided into the L blocks of M-bit data and each block being assigned to each superblock;
• a combination unit for combining the blocks of data outputted from the F-function unit with the blocks of data selected in the second selection unit by XOR;
• and
• an output unit for outputting N blocks of data arranged in the same order as the initial N blocks, the blocks selected in the first selection unit being outputted without any change and the other blocks being the outputs of the second selection unit.

A method for encrypting input data after dividing the input data into N blocks of data each consisting of M bits, wherein N is an integer greater than 2 and M is an integer greater than 1, the data encryption apparatus comprising:

• selecting 1 to N-1 blocks among the N blocks by a first selection unit, using a block selection key;
• selecting all the other blocks by a second selection unit;
• combining the blocks of data selected in the first selection unit into a single block of data and outputting the M-bit data by a first combination unit;
• encrypting the M-bit data outputted from the first combination unit using a data encryption key and outputting resultant M-bit data by an F-function unit for;
• combining the M-bit data outputted from the F-function unit with each of the blocks of data selected in the second selection unit by a second combination unit;
• and
• outputting N blocks of data arranged in the same order as the initial N blocks, the blocks selected in the first selection unit being outputted without any change and the other blocks being the outputs of the second combination unit.

A method of encrypting input data after dividing the input data into N blocks of data each consisting of M bits, wherein N is an integer greater than 2 and M is an integer greater than 1, the data encryption apparatus comprising:

• selecting L blocks among the N blocks by a first selection unit, L being an integer of 1 to N-2;
• generating block selection information, based on a block selection key and the blocks of data outputted from the first selection unit by a block selection information generation unit for;
• selecting 1 to N-L-1 blocks among N-L blocks that are selected in the first selection unit by a second selection unit for using the information outputted from the block selection information generation unit;
• selecting all of the other blocks that are not selected in the first and second selection units by a third selection unit;
• combining the blocks of data selected in the first and second selection units into a single block of data and outputting the M-bit data by a first combination unit;
• encrypting the M-bit data outputted from the first combination unit using a data encryption key and outputting resultant M-bit data by an F-function unit;
• combining the M-bit data outputted from the F-function unit with each of the blocks of data selected in the third selection unit by a second combination unit by XOR;
• and
• outputting all the blocks of data outputted from the first and second selection units and the second combination unit by an output unit after permuting all the blocks.

A method for encrypting input data after dividing the input data into N blocks of data each consisting of M bits, wherein N is an integer greater than 2 and M is an integer greater than 1, the data encryption apparatus comprising:

• grouping the N blocks into L superblocks by a grouping unit, L being an integer of more than 1;
• selecting one block from each of the superblocks using a block selection key by a first selection unit;
• selecting all the other blocks in each of the superblocks by a second selection unit;
• encrypting L blocks of data selected in the first selection unit using a data encryption key and outputting the encrypted L blocks of data, the encrypted blocks of data being divided into the L blocks of M-bit data and each block being assigned to each superblock;
• combining the blocks of data outputted from the F-function unit with the blocks of data selected in the second selection unit by a second combination unit by XOR;
• and
• outputting N blocks of data arranged in the same order as the initial N blocks, the blocks selected in the first selection unit being outputted without any change and the other blocks being the outputs of the second selection unit.

An apparatus for encrypting input data, the input data consisting of a predetermined number greater than 2 of input data blocks, the apparatus comprising:

• selection means for selecting a number of input data blocks from the predetermined number of input data blocks, the selection means using a block selection key;
• a first combination unit operatively connected to the selection means for forming a first combination from the selected number of input data blocks;
• an encryption unit for accepting and encrypting the first combination, thereby forming an encrypted result, the encryption unit using an encryption key;
• a second combination unit for forming a second combination from the encrypted result and from a number of input data blocks not selected by the selection means;
• and
• means operatively connected to the selection means and the second combination unit, for outputting both the second combination and the selected number of input data blocks.