Network Security

1. Consider the simple substitution-permutation network discussed in class. Show how you get the ciphertext from the plaintext through XORing the round keys, performing the substitutions, and the permutations.

2. Factorize 96037 by brute force. You can find a list of prime numbers. Remember that you have to try all prime numbers till 96037. You can write code to do this in Java, C, Swift, Python, or another language of your choice.

3. Consider a simple (not secure) version of RSA. Here n = 7´11 = 77 and F(n) = 6´10 = 60. If the public key is b = 11, find the ciphertext y if the plaintext is x =10. If Bob gets this ciphertext from Alice, what does he need to compute.