A.
They are used to add randomness to the encryption process
B.
They ensure that two identical plaintext values result in different ciphertext values when encrypted with the same key
C.
They provide extra protection in case an implementation is using the same symmetric key more than one time
D.
They are XORed to the plaintext after encryption to ensure more randomness to the process
Explanation:
Initialization vectors (IVs) are random values that are used with
symmetric algorithms to ensure that patterns are not created during the encryption
process. They are usually used as seeding values or starting points and do not need
to be encrypted when being sent to the destination. If IVs were not used, then two
identical plaintext values that are encrypted with the same key could create the
same ciphertext.