solve step by step

18. Encode the message "Attack at Dawn" with a Vigenere's cipher, using the keyword "KEY". 19. Decrypt the message "MLHMT FIYKK BHKZF USQNQ GNJMF BORGC XPNID QTOKK FY" using the key "magic". 20. The following message has been encrypted with the autokey scheme with key letter C. Decrypt the message. "RDFKT SXFMQ ESSCT PNIHZ ZUOAL KVWLL GBGAL FPCYN HJZLK BDDAD TBXVR RLGZB HBA". 21. Compare Vigenre cipher with the autokey scheme. Which is easier to encrypt? Decrypt? What are potential problems with encryption? Decryption