EXTENSION RC4 ENCRYPTION METHOD USING LFSR(LINEAR FEEDBACK SHIFT REGISTER)

摘要

PURPOSE: An extension RC4 encryption method using LFSR(Linear Feedback Shift Register) is provided to enlarge short period according to encryption key arrangement by using LFSR encryption method and to perform safe and high speed operation by complementing the frailty to attack. CONSTITUTION: An extension RC4 encryption method using LFSR(Linear Feedback Shift Register) comprises the steps of; defining two dimension S-box and initiating the low and column of two dimension arrangement S-box as linear(S100); reconstructing previous given encryption key data by using LFSR or GLFSR(Galois way); swapping concerned column of S-subbox by reconstructed encryption key data in order and rearranging the S-box randomly(S200); generating S_EOR to be used in encryption step by specific column data of rearranged S-box(S300); and encrypting plain text by generated S_EOR and linear and random state counter.