1. Why did we set cc_n (Unicode)= 1114112? Explain whether the recoverability property may fail if we set cc_n(Unicode) to a bigger number or remove % cc_n for both cc_encrypt_character and cc_decryptcharacter.

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Out [7]: 'A' The character 'F' is decrypted back to 'A' because (char_code key) % cc_n reverse cyclic shifts the code by the key 5. Encryption Decryption char A B C D E (chr(ord(char) - key) % cc_n) ord(char) 65 66 67 68 69 70 (ord(char) - key) % cc_n (ord(char) + key) % cc_n 70 71 72 73 74 75 ord(char) (chr(ord(char) + key) % cc_n) F G H J K char Exercise Why did we set cc_n = 1114112 ? Explain whether the recoverability property may fail if we set cc_n to a bigger number or remove % cc_n for both cc_encrypt_character and cc_decrypt_character. Out [7]: 'A' The character 'F' is decrypted back to 'A' because (char_code key) % cc_n reverse cyclic shifts the code by the key 5. Encryption Decryption char A B C D E (chr(ord(char) - key) % cc_n) ord(char) 65 66 67 68 69 70 (ord(char) - key) % cc_n (ord(char) + key) % cc_n 70 71 72 73 74 75 ord(char) (chr(ord(char) + key) % cc_n) F G H J K char Exercise Why did we set cc_n = 1114112 ? Explain whether the recoverability property may fail if we set cc_n to a bigger number or remove % cc_n for both cc_encrypt_character and cc_decrypt_character.

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Exercise Define the function ccattack that takes as arguments a string ciphertext ... View the full answer