Window Help HW_3.pdf (page 1 of 2) 1. Explain the following concepts briefly but to the point: 1) Symmetric cryptography vs. asymmetric cryptography 2) Kerckhoffs principle 3) Key space vs. key length 4) Confusion vs. diffusion 5) Feistel network vs. Substitution-Permutation Network (SPN) 6) Block cipher vs. stream cipher 7) For AES, what are the block size and key length(s)? How many rounds does A 8) What are the four layers in each round of AES? I 9) How many subkeys does DES-128 need? What is the length of a subkey? 10) What are the two operations within the AES S-Box? 2. Generate the multiplication table for the extension field GF(23) for the cas irreducible polynomial is P(x)=x+x + 1. The multiplication table is in this table.