Questions:

1. Diagram each of the encryption modes:
   Electronic Code Book (ECB), Cipher Block Chaining (CBC),
   Cipher FeedBack (CFB), Output FeedBack (OFB).
   (T/F) Among the 4 encryption modes above, ECB and CBC
   require both Encryption and Decyption boxes while CFB and OFB
   only require the Encryption box.

2. (T/F) A Feistel cipher which is defined using an identity
   f-box mapping is given by F(a,b) = (b,a XOR b).

3. (T/F) The inverse of the ASCII character ESC modulo the AES
   polynomial X^8 + X^4 + X^3 + X + 1 is the ASCII character ACK.

4. (T/F) The polynomial X^3 + X + 1 is irreducible.

5. (T/F) In the Blum-Rabin coin-tossing protocol, 
   Alice can factor Bob's modulus with probability 1/2.

6. (T/F) In the Fiat-Shamir zero-knowledge proof for Quadratic
   Residues, the Verifier can never learn the square root 
   of the first number sent in the protocol.

7. (T/F) If n is a Blum integer, then n-1 is a pseudosquare modulo n.