KEY MANAGEMENT
One method for distributing key information is manually.
This is fine for a small number of nodes but runs into administrative problems, N users requires (N * N-1)/2 keys.
Authentication among 100 nodes would require 4950 key pairs, where each key must be kept private and distributed in a secure manner.
Manual key distribution is not feasible for MANET authentication except with small numbers of nodes.
Key distribution via Certificates allows very large MANET networks