Rijndael block cipher apparatus and encryption/decryption method thereof

A rijndael block decryption apparatus having M-bit input data and N-bit input keys and decrypting the M-bit input data by repeating for a predetermined number of times a round operation that includes transforms of inverse shift_row, inverse substitution, add-round-key and inverse mixcolumn, the apparatus comprising:

• a round operation unit including a round operation execution unit for processing the data in the unit of M/m bits (where m is 2, 3 or 4) at least in the transforms of inverse substitution, add-round-key and inverse mixcolumn, and a round key generation unit for generating round keys in order to provide the round keys in the transform of add-round-key;
• a round operation control unit for controlling the round operation performed by the round operation unit;
• and
• a data storage unit for storing M/m-bit intermediate data generated by the round operation unit at an intermediate stage of every round and M-bit data generated at an end stage of every round,
• wherein the round keys generated in the round key generation unit is added to an upper M/m input data in the round operation execution unit while simultaneously begin processing of a lower M/m input data in the round operation execution unit before the end stage of every round for the upper M/m input data in the round operation execution unit at a same clock cycle without the upper M/m input data and the lower M/m input being processed in any one of a same transform of the transforms comprising of at least the substitution, mixcolumn and add-round-key,
• wherein the end stage of every round indicates that the data in the unit of M/m bits (where m is 2, 3 or 4) have been processed in all of the at least transforms of the substitution, mixcolumn and add-round-key, and
• wherein the processing of the upper M/m input data and the lower M/m input data are transformed in a same manner of a same circuit for each of the at least transforms of the substitution, mixcolumn and add-round-key.

A rijndael block cipher apparatus having M-bit input data and N-bit input keys, and encrypting the M-bit input data by repeating for a predetermined number of times a round operation for encryption that includes transforms of shift_row, substitution, mixcolumn and add-round-key or decrypting the M-bit input data by repeating for a predetermined number of times a round operation for decryption that includes transforms of inverse shift_row inverse substitution, add-round-key and inverse mixcolumn, the apparatus comprising:

• a round operation unit including a round operation execution unit for processing the data in the unit of M/m bits (where m is 2, 3 or 4) at least in the transforms of substitution, mixcolumn and add-round-key in an encryption mode and for processing the data in the unit of M/m bits (where m is 2, 3 or 4) at lease in the transforms of inverse substitution, add-round-key and inverse mixcolumn in a decryption mode, and a round key generation unit for generating round keys in order to provide the round keys in the transform of add-round-key;
• a round operation control unit for controlling the round operation performed by the round operation unit;
• and
• a data storage unit for storing M/m-bit intermediate data generated by the round operation unit at an intermediate stage of every round and M-bit data generated at an end stage of every round,
• wherein the round keys generated in the round key generation unit is added to an upper M/m input data in the round operation execution unit while simultaneously begin processing of a lower M/m input data in the round operation execution unit before the end stage of every round for the upper M/m input data in the round operation execution unit at a same clock cycle without the upper M/m input data and the lower M/m input being processed in any one of a same transform of the transforms comprising of at least the substitution, mixcolumn and add-round-key,
• wherein the end stage of every round indicates that the data in the unit of M/m bits (where m is 2, 3 or 4) have been processed in all of the at least transforms of the substitution, mixcolumn and add-round-key, and
• wherein the processing of the upper M/m input data and the lower M/m input data are transformed in a same manner of a same circuit for each of the at least transforms of the substitution, mixcolumn and add-round-key.

A rijndael block encryption method for receiving M-bit input data and N-bit input keys and performing a round operation of the input data for a predetermined number of times, the method comprising:

• a round operation step of performing a round operation with respect to all m data of M/n bits, the round operation including sub-steps of a shift_row transform for performing a shift_row of the M-bit data from a previous round and outputting only M/m-bit (where m is 2, 3 and 4) data corresponding to a selection signal to a next step, a substitution transform for performing a substitution of the M/m-bit data, a mixcolumn transform for performing a mixcolumn of the M/m-bit data, and an add-round-key transform for performing an addition of round keys having the same size to the M/m-bit data, respectively;
• and
• a round key generation step of generating the round keys in order to provide the round keys at the sub-step of the add-round-key transform,
• wherein the round keys generated in the round key generation unit is added to an upper M/m input data in the round operation execution unit while simultaneously begin processing of a lower M/m input data in the round operation execution unit before the end stage of every round for the upper M/m input data in the round operation execution unit at a same clock cycle without the upper M/m input data and the lower M/m input being processed in any one of a same transform of the transforms comprising of at least the substitution, mixcolumn and add-round-key,
• wherein the end stage of every round indicates that the data in the unit of M/m bits (where m is 2, 3 or 4) have been processed in all of the at least transforms of the substitution, mixcolumn and add-round-key, and
• wherein the processing of the upper M/m input data and the lower M/m input data are transformed in a same manner of a same circuit for each of the at least transforms of the substitution, mixcolumn and add-round-key.

A rijndael block decryption method for receiving M-bit input data and N-bit input keys and performing a round operation of the input data for a predetermined number of times, the method comprising:

• a round operation step of performing a round operation with respect to all m data of M/n bits, the round operation including sub-steps of an inverse shift_row transform for performing an inverse shift_row of the M-bit data from a previous round and outputting only M/m-bit (where m is 2, 3 and 4) data corresponding to a selection signal to a next step, an inverse substitution transform for performing an inverse substitution of the M/m-bit inverse-shift_row-transformed data, an add-round-key transform for performing an addition of round keys having the same size to the M/m-bit inverse-substitution-transformed data, respectively, and an inverse mixcolumn transform for performing an inverse mixcolumn of the M/m-bit add-round-key-transformed data;
• and
• a round key generation step of generating the round keys in order to provide the round keys at the sub-step of the add-round-key transform,
• wherein the round keys generated in the round key generation unit is added to an upper M/m input data in the round operation execution unit while simultaneously begin processing of a lower M/m input data in the round operation execution unit before the end stage of every round for the upper M/m input data in the round operation execution unit at a same clock cycle without the upper M/m input data and the lower M/m input being processed in any one of a same transform of the transforms comprising of at least the substitution, mixcolumn and add-round-key,
• wherein the end stage of every round indicates that the data in the unit of M/m bits (where m is 2, 3 or 4) have been processed in all of the at least transforms of the substitution, mixcolumn and add-round-key, and
• wherein the processing of the upper M/m input data and the lower M/m input data are transformed in a same manner of a same circuit for each of the at least transforms of the substitution, mixcolumn and add-round-key.