1. (10 points) Draw the special purpose hardware organization for the following algorithm: Input: Ciphertext stored in four w-bit input registers A, B, C, D Number r of rounds w-bit round keys S[0; :::; 2r + 3) Output: Plaintext stored in A,B,C,D Procedure: C = C-S[2r + 3] A=A-[2r + 2] for i= r downto 1 do { (A,B,C,D) = (D; A;B;C) u = (D * (2D + 1))>>t) + u A = ((A - S[21])>>>u) + t D =D - S[1] B = B-S[0]