2. Computations(20 marks, 4 marks for each) (1) 35mod8= (2) (18+35)mod11= (3) 1312mod10= (4) 323mod7= (5) (19)=(21)= 3. Single Choise(10 marks, 2 marks for each) (1) In Shift Cipher, if the plaintext d is encrypted to be L, the ciphertext of plaintext g is ( ) A. 0 B. P C. Q D. N (2) DES has ( ) rounds. A. 10 B. 12 C. 16 D. 64 (3) In DES, the input of S-box S1 is x=100000, the output S1(x)=() A. 1000 B. 0100 C. 0010 D. 0110 (4) Each block of AES has ( ) bits. A. 64 B. 56 C. 128 D. 256 (5) Symmetric ciphers are divided into stream ciphers and ciphers. A. public-key B. classical C. shift D. block