a) Differentiate between encryption and decryption.

b) Explain how cryptography works.

c) List down three examples of symmetric key algorithms and two examples of asymmetric encryption algorithms.

d) Explain using suitable illustrations where necessary how asymmetric public key encryption ensures both confidentiality and authenticity.

e) Explain the role of the following players in a Public Key Infrastructure (PKI)

(i) Certification authority
(ii) Certificate holder
(iii) Relying party