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Kizspy. me Q1 (1 point). What is the prime factorization of 491400?
Q2 (1 point). You agreed to use a Caesar cipher with a key of k = 3 with a colleague.
While in a lecture, the colleague passes you a note that says "WKLV LV D VHFUHW".
Decrypt the message.
Q3 (1 point). Suppose you forgot the key for a Caesar cipher. How many decryption
computations of the cipher text "OCSFX" do you need to perform to reach the plaintext?
Q4 (1 point). Using the Permutation Cipher with the key [2143], what is the plaintext
for the ciphertext AUXSGDERXFAX? (The unfilled matrix is filled with letter 'X',
remove it to get the final answer).
Q5 (1 point). What is the Euler totient function of 210?
Q6 (1 point). In RSA cryptosystem, if p = 11, q = 17, and e=3, what is the value of o(n)
where q(n) is the Euler Totient function of n and n is the modulus?
Q7 (1 point). Using the same RSA parameters from Q6, with p = 11, q=17, e=3, and
the private key d = 227, what is the ciphertext C when encrypting the message M = 5?
Q8 (1 point). In an RSA cryptosystem with p = 11, q=17, and e = 3, an attacker
performs a chosen-ciphertext attack. If the attacker has ciphertext 10 and wants to find
the corresponding plaintext, they compute c' = c*r^e mod n and choose r = 2. If the new
ciphertext c' = 80, and the corresponding decryption is 120, what is the plaintext
corresponding to the original ciphertext 10?
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