Alice encrypted two messages M1 and M2 into C1 and C2 using AES, and sent them to Bob separately. M1 and M2 are identical except for the 19th byte. Unfortunately, Darth had learnt M1, C1 of 80 types each, and eavesdropped C2 in the same order as message M2 encrypted in blocks. If Darth can also guess out the cipher block mode that Alice used for these messages, which information can he determine? (Hints: select TWO answers for each question below for AES with a block length of 128 bits.)

Assuming AES-CTR (Counter) mode, if Alice used same counter sequence when she encrypted the two messages, then Darth can determine

A. M2 contains 80 bytes.

B.M2 is less than or equal to 80 bytes long but not the exact length.

C. The entire plaintext for M2 except for the 2nd block.

D. The entire plaintext for M2.

Assuming AES-CBC (Cipher Block Chaining) mode, if Alice used the same IV when she encrypted the two messages, then Darth can determine

A.M2 contains 80 bytes.

B.M2 is less than or equal to 80 bytes long but not the exact length.

C.The plaintext for only the first block of M2.

D.The entire plaintext for M2.

Assuming AES-ECB (Electronic Code Book) mode, then Darth can determine

A.M2 contains 80 bytes.

B.M2 is less than or equal to 80 bytes long but not the exact length.

C.The plaintext for only the first block of M2.

D.The entire plaintext for M2.

These are all multiple chocie questions