Cryptography & Network Security

Public Key Infrastructure (PKI).

(d)Figure 2 shows an instance of a web of trust generated after a series of PGP key exchanges. An arrow from node X to node Y indicates that the certificate of X was signed by Y . Fully shaded nodes are trusted by A. Half-shaded nodes are partially trusted by A.

State which of the nodes have certificates that A considers to be trusted. In each case,

explain why does A trust that nodes certificate.

A E G H 1 J Figure 2: Problem 1(d)