Suppose that Alice and Bob use CBC mode encryption. a. What security problems arise if they always use a fixed initialization vector (IV), as opposed to choosing IVs at random? Explain. b. Suppose...

Suppose that Alice and Bob use CBC mode encryption.

a. What security problems arise if they always use a fixed initialization vector (IV), as opposed to choosing IVs at random? Explain.

b. Suppose that Alice and Bob choose IVs in sequence, that is, they first use 0 as an IV, then they use 1 as their IV, then 2, and so on. Does this create any security problems as compared to choosing the IVs at random?