Arithmetic method and apparatus for supporting aes and aria encryption/decryption functions

Abstract

Provided are an arithmetic method and apparatus for supporting Advanced Encryption Standard (AES) and Academy, Research Institute and Agency (ARIA) encryption/decryption functions. The apparatus includes: a key scheduler for generating a round key using an input key; and a round function calculator for generating encrypted/decrypted data using input data and the round key. Here, the round function calculator includes an integrated substitution layer and an integrated diffusion layer capable of performing both AES and ARIA algorithms.

1 . An arithmetic method of supporting Advanced Encryption Standard (AES) and Academy, Research Institute and Agency (ARIA) encryption/decryption functions, the method comprising the steps of:
 receiving input data and a round key;   performing an S-box operation used in common in AES and ARIA algorithms using the input data and the round key; and   extracting the common terms used in a diffusion function of the AES and ARIA algorithms using the data on which the S-box operation is performed, and performing a diffusion operation.   
     
     
         2 . The arithmetic method of  claim 1 , further comprising the step of:
 performing key expansion using the input key and thereby generating the round key.   
     
     
         3 . The arithmetic method of  claim 1 , wherein an AES and ARIA-integrated diffusion layer performs the diffusion operation selectively using one of an AES MixColumns function, an AES InvMixColumns function and an ARIA diffusion function. 
     
     
         4 . The arithmetic method of  claim 3 , wherein the integrated diffusion layer shares the common terms of the AES MixColumns function, the AES InvMixColumns function and the ARIA diffusion function.