METHOD FOR ENHANCING CRYPTOGRAPHY OPERATION

A METHOD OF ENCRYPTING (10) A PLAINTEXT WITH ENHANCED SECURITY IN CRYPTOGRAPHY OPERATION, COMPRISES STEPS OF RECEIVING THE PLAINTEXT TO BE ENCRYPTED, GENERATING AN INITIAL ROUND (11) BY PERFORMING ADDROUNDKEY FUNCTION (14) WITH A FIRST KEY EXPANSION (15), GENERATING SUBSEQUENT ROUNDS (26) BASED ON THE OUTPUT FROM GENERATED INITIAL ROUND (11) BY PERFORMING BYTESUB (18), SHIFTROW (19), MIXCOLUMN (20) AND ADDROUNDKEY (23) FUNCTIONS, WHEREIN THE ADDROUNDKEY FUNCTION (23) IS PERFORMED USING A FIRST KEY SCHEDULE (25), AND GENERATING A FINAL ROUND (27) BY PERFORMING BYTESUB (28), SHIFTROW (29) AND ADDROUNDKEY (32) FUNCTIONS WHEREIN THE ADDROUNDKEY FUNCTION (32) IS PERFORMED USING THE FIRST KEY EXPANSION (15) TO TRANSFORM THE PLAINTEXT TO CIPHERTEXT. A BOOLEAN AND ROTATION FUNCTION (12, 21, 30) FOLLOWED BY AN ADDITIONAL ADDROUNDKEY FUNCTION (13, 22, 31) WHICH ARE KEY-BASED ARE PERFORMED BEFORE THE ADDROUNDKEY FUNCTION (14, 23, 32) IN EACH ROUNDING STAGE.