Q1) Given that the current anti-replay window used by IPsec to detect replay packets spans from 110 to 320, if the next 3 incoming packets have the following sequence numbers, respectively:
1) 180
2) 90
3) 400
for each of the above cases, describe what the receiver will do with the packet and if there are changes in the window's parameters or not. Desscribe what the parameters of the window after that will be if there are changes in the parameters.
Q2) In a Diffie-Hellman (DH) exchange between Alice and Bob without protections against active attacks, two messages are used, i.e., Alice sends a number YA to Bob, and Bob sends another number YB to Alice.
However, the DH exchange is vulnerable to an MiM attack. To protect the DH exchange against the MiM attack, Alice will use her private key, KPrivateAlice, to protect her number YA, and Bob will use a share secret with Alice, KAB, to protect his number YB. Show how the numbers are protected by listing the two modified messages in symbolic format. (If there are more protections or messages in the answer, only the first two will be marked.)
Briefly describe how Bob verifies that Alice's number YA has not been attacked by the MiM attack.