URGENT

(c) Show how the 2. (a) Explain how a denial of service attack is perpetrated. (b) Laura Itzel Lujan and Srivani Lekkala want to discuss their plans for a startup company through messages encrypted with a symmetric key. Explain, with the help of a message sequence diagram, how Laura, the initiator of the discussion, would obtain symmetric key for the session from a trusted key distribution center (KDC) and pass it onto Srivani without any risk of person- in-the-middle attack or any knowledge about Srivani's public key. (3 Points) (e) Jared Christopher Riley wants to send Ethan Richard Adams a secure email about a strategic decision about their company. The email with safeguards for data encryption, message integrity, and mutual authentication, uses Ethan's public key, Jared's private key, and the shared symmetric key between them. With the help of block diagram depicting components of secure email system at both sender (Jared) and receiver (Ethan) ends, describe how the aforementioned safeguards can be achieved. (4 Points) (d) Discuss how Jared and Ethan get each other's public keys from a certification authority. (1 Point)