4.) In class we learnt about Cipher Block Chaining (CBC) where using an Initialization Vector (IV) helped us in sending the same repeated blocks of message as encrypted outputs with each output block is shown being different. (a) Consider a 4-bit input block scenario and depict at least 1 choice of events where CBC will fail to produce different set of outputs. (b) Interpret your above result and signify why choosing the input-output block pairing and IV in random drastically reduces the chance of this happening. (c) For a given k-bit IV that we know for sure and a known repeating block of k-bit input message stream in the format (1011 1011 1011 1011) calculate the number of possibilities of (a) happening. 4.) In class we learnt about Cipher Block Chaining (CBC) where using an Initialization Vector (IV) helped us in sending the same repeated blocks of message as encrypted outputs with each output block is shown being different. (a) Consider a 4-bit input block scenario and depict at least 1 choice of events where CBC will fail to produce different set of outputs. (b) Interpret your above result and signify why choosing the input-output block pairing and IV in random drastically reduces the chance of this happening. (c) For a given k-bit IV that we know for sure and a known repeating block of k-bit input message stream in the format (1011 1011 1011 1011) calculate the number of possibilities of (a) happening