? Alternatively, what is the remainder when 128 raised to 128 is divided by 7?

Which of the following BEST describes the security offered by the Diffie-Hellman key-exchange protocol (assuming the DDH problem is hard)?

Define the generator G by G(x) = x | x. (G maps inputs of length n to outputs of length 2n). Which of the following algorithms A distinguishes the output of G from uniform?

Which of the following is a drawback of the private-key setting that is NOT addressed by the public-key setting?

What is the size of key space |K| for a shift cipher, considering the message space as English alphabets, and encryption algorithm as Enc​(m)=(m+shift)mod 26?

If the message “cryptoisfun” is encrypted with the shift cipher and key 25. What is the resulting ciphertext?

Say G is in the subgroup Z*11, generated by g = 4. Let’s say, the group has order 5.  The public key contains h = 3. What is encryption of the message m = 5, using the secret exponent y = 3?

What is 7th root of 2 modulo 33? (Note that ϕ(33) = 20, and 3 . 7 = 1 mod 20)

Which of the following is the most appropriate primitive for achieving message integrity between two users sharing a key?

3-1 mod 7 = ? Alternatively, what is the inverse of 3 mod 7 on multiplication?