Cipher Block Chaining (CBC) a. Sketch the flows for two successive CBC decryptions, with ciphertexts C1, C2 and plaintexts P1, P2. b. Write the formula that links the plaintext P2 with the ciphertexts C2 and 61 c. P2 = ...................... If he ciphertext blocks: C1, C2, we have C1 = C2, then what can you say about the corresponding plaintexts P1, P2? d. If in CBC there is a l-bit error in the ciphertext C1 then the decrypted plaintext P1, P2 are obviously corrupted. Are any blocks beyond P2 corrupted (assuming no more bits are corrupted)? Cipher Block Chaining (CBC) a. Sketch the flows for two successive CBC decryptions, with ciphertexts C1, C2 and plaintexts P1, P2. b. Write the formula that links the plaintext P2 with the ciphertexts C2 and 61 c. P2 = ...................... If he ciphertext blocks: C1, C2, we have C1 = C2, then what can you say about the corresponding plaintexts P1, P2? d. If in CBC there is a l-bit error in the ciphertext C1 then the decrypted plaintext P1, P2 are obviously corrupted. Are any blocks beyond P2 corrupted (assuming no more bits are corrupted)