Which of the following elements is not included in a Public Key Infrastructure (PKI)?

A.
Timestamping

B.
Lightweight Directory Access Protocol (LDAP)

C.
Certificate revocation

D.
Internet Key Exchange (IKE)

Explanation:
Public key cryptography is one mechanism that is often used to fulfill the security
requirements necessary to conduct electronic transactions over public networks.
PKI (public key infrastructure) and cryptography based solutions are taking the lead in secure ecommerce. PKI addresses nonrepudiation of identity using a dual-key encryption system that
allows users to uniquely sign documents with a digital signature. Public key cryptography uses
pairs of keys, each pair consisting of one public key and one private key. Information encrypted
with one key in the pair can only be decrypted with the other key. LDAP is issued to bring user
information and Timestamping to track changes over time. PKI also relies on certificated and CRL
(Certificate Revocation list) to discard compromised, expired digital certificates.