could you answer A,b,c&d

2. (a) Explain how a denial of service attack is perpetrated. (1 Point) (b) Danah Omary and Deja Fowler 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 Danah, the initiator of the discussion, would obtain symmetric key for the session from a trusted key distribution center (KDC) and pass it onto Deja without any risk of person-in-the-middle attack or any knowledge about Deja's private key. (3 Points) (c) Taylor Graf wants to send Hae Kim a secure email about a strategic decision about their company. The email with safeguards for data encryption, message integrity, and mutual authentication, uses Taylor's public key, Hae'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 (Taylor) and receiver (Hae) ends, describe how the aforementioned safeguards can be achieved. (4 Points) (d) Discuss how Taylor and Hae get each other's public keys from a certification authority. 2. (a) Explain how a denial of service attack is perpetrated. (1 Point) (b) Danah Omary and Deja Fowler 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 Danah, the initiator of the discussion, would obtain symmetric key for the session from a trusted key distribution center (KDC) and pass it onto Deja without any risk of person-in-the-middle attack or any knowledge about Deja's private key. (3 Points) (c) Taylor Graf wants to send Hae Kim a secure email about a strategic decision about their company. The email with safeguards for data encryption, message integrity, and mutual authentication, uses Taylor's public key, Hae'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 (Taylor) and receiver (Hae) ends, describe how the aforementioned safeguards can be achieved. (4 Points) (d) Discuss how Taylor and Hae get each other's public keys from a certification authority