Question

2. Let ( F ) be a block encryption function of ( n ) bits, with keys of the same size. A random key ( k ) is chosen. a) Calculate the probability (in terms of ( n )) that exactly for two blocks ( m ), ( F_k(m) = m ), that is, the permutation ( F_k ) has exactly two fixed points. b) Calculate these probabilities for ( n = 128 ) and for ( F = ext{AES} ). Remember that ( F_k ) is a permutation, but the key space limits the number of permutations that can be used; nonetheless, you can assume that ( F_k ) is a randomly chosen permutation from the set of all permutations. Hint: The concept of Derangement can help you easily calculate and express the requested probabilities. Please explain it to me very detailed, because I'm very lost. Thank you!

Name: 2 let f be a block encryption function of n bits with keys of the same size a random key k is chosen a calculate the probability in terms of n that exactly for two blocks m fkm m that is th 47686
Uploaded: 2023-12-17T20:58:56-08:00
Duration: 2 min 18 s
Channel: Akash M
Description: 2 let f be a block encryption function of n bits with keys of the same size a random key k is chosen a calculate the probability in terms of n that exactly for two blocks m fkm m that is th 47686

          2. Let ( F ) be a block encryption function of ( n ) bits, with keys of the same size. A random key ( k ) is chosen.
a) Calculate the probability (in terms of ( n )) that exactly for two blocks ( m ), ( F_k(m) = m ), that is, the permutation ( F_k ) has exactly two fixed points.
b) Calculate these probabilities for ( n = 128 ) and for ( F = 	ext{AES} ).
Remember that ( F_k ) is a permutation, but the key space limits the number of permutations that can be used; nonetheless, you can assume that ( F_k ) is a randomly chosen permutation from the set of all permutations.
Hint: The concept of Derangement can help you easily calculate and express the requested probabilities.
Please explain it to me very detailed, because I'm very lost. Thank you!

Added by Jessica M.

Question

Please give Ace some feedback