IPSec 

a) Describe the process of the Diffie-Hellman Key Exchange protocol. What kind of attacks does it face? How to fix it to make it secure? (8 marks)

b) The Internet Security Protocol (IPSec) is widely used to secure the cloud network. IPSec can be implemented in a host-to-host transport mode as well as a network tunneling mode. Compare transport mode and tunnel mode.  (6 marks)