1. Using the basic ciphers we discussed in class, provide the plaintext for the following ciphertext. "LRF LBH SBHAQ GUR EVTUG NAFJRE". Explain the parameter used in the cipher to generate the ciphertext. [20 points] Hints: The plaintext is uritten in Englisb and if employs tbe simplest apber we discussed. Feel free to use online tools. ue discussed in class. 2. Random J. Protocol-Designer has been told to design a scheme to prevent messages from being modified by an intruder. Random J, decides to append to each message a hash of that message. Why doesn't this solve the problem? (Short Answer) [20 points] 3. Suppose Alice, Bob, and Carol want to use secret key technology to authenticate each other. If they all used the same secret key K, then Bob could impersonate Carol to Alice (actually any of the three can impersonate the other to the third). Suppose instead that each had their own secret key, so Alice uses Julio Arainz, anauz@ohio edu Sep/2023 ton: 1.0 ITS-4530-5530-HW-LAB-02 KA, Bob uses KB, and Carol uses KC. This means that each of Alice, Bob, and Carol, to prove his or her identity, responds to a challenge with a function of his or her secret key and the challenge. Is this more secure than having them all use the same secret key K ? (Hint: what does Alice need to know in order to verify Carol's answer to Alice's challenge?) (Short Answer) [20 points]