1. Bob wants to use DES to make a secured communication withAlice using DES key ‘Kb’ to encrypt and decrypt data. Bob uses PKImethod to distribute the DES key to Alice. If Alice private key is‘Kpa’, and her public key is ‘Kpb’. Please describe the processthat Bob can send his DES key ‘Kb’ to Alice securely.
2. You receive a message that was encoded using a block encodingscheme with the encoding matrix
M=3275
- Verify by computing M'×M thatM'=524193
(remember to wrap around if a value is> 25.)
- Decode the ciphertext message MXOSHI.
