Answer Happy

(a). Pwrite down which of the following womentar Team Kerckbod principle statem that the cipher methodowed secret, and it must bot be able to fall into the lands of the enemy way out In perfect socrocy, the key space should be at least themes . Coeur's cher encrypts the age by shifting each alphabet to be random number of places forward . In block cipliers, the counter mode provides more security compared to the electronic code book mode . Authenticated encryption schemes ensure data confidentiality but not Integrity (10 pts) (b). Please explains why MAC schemes assume that a private key is shared between the parties in order to achieve message integrity, (10 pts

Problem (20 pts) (a). Please write down which of the following statements are ) Kerckhof principle states that the cipher method must be required to secret, and it must not be able to fall into the hands of the enemy at any . In perfect secrecy, the boy wpisce should be at to the men space . Caesar's cipher encrypts the most by shifting ench spluabet to wome random number of places forward In block ciphers, the counter mode provides more security compared to the electronic code book mode - Authenticated encryption schemes ensure datn confidentiality but not dat integrity (10 pts) (b). Please explain why MAC schemes assume that a private key is shared between the parties in order to achieve message integrity. (10 pts)