IPSec documentation allows combining the security associations. Discuss why is it

recommend to perform ESP protocol before AH protocol? $(10$ points$)$Suppose Alice has a secret a and Bob has a secret $b.$ Alice and Bob also have access to

a secure communication channel. The goal is to let a server $s$ compute ${\displaystyle \underset{?}{\overset{?}{}}}=ao+b.$

However, they don't want $s$ learn $a$ or $b.$ How can they achieve this. $(10$ points$)$IPSec documentation allows combining the security associations. Discuss why is it

recommend to perform ESP protocol before AH protocol? $(10$ points$)$